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Cell and Developmental Biology > Regulation and Signalling > Flashcards

Regulation and Signalling Flashcards

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1
Q

When was the first multicellular algae?

A

1.5 billion years ago

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2
Q

How did multicellularity arise?

A
  • Multiple times during eukaryotic evolution
  • Evolved independentlu
  • Last common ancestor was unicellular
  • Good advantages to being multicellular
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3
Q

What are the advantages to being multicellular?

A
  • Bigger = better protection from predation
  • More buffered from the environment → internal environment
  • Allows development of different cell types with specialized functions within organisms
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4
Q

What is the flagellar synthesis constraint hypothesis?

A
  • Cells with flagella allow movement
  • Micro-tubule (required for cell division)
  • Cell with flagella is unable to divide
  • Evolutionary pressure = need specialization
  • Presence of both allows movement and division
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5
Q

Why is the balance between differentaited cell types important?

A
  • Don’t want one type vs another

- Need to coordinate

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6
Q

Describe cell communication in multicellularity

A

Need to sense extracellular and intracellular environment

Recognition of self and non-self

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7
Q

Describe cell adhesion in multicellular orgnaisms

A

Multicellular organisms need to stick together

Complex system

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8
Q

Why does there need to be cell signalling?

A
  1. Homeostasis and maintanence
  2. Process of development
  3. Cells have to reach their 3D position
  4. Put in righ place at the righ time
  5. Make the decision to become specilaised
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9
Q

What are choanoflagellates?

A
  • Ancestral unicellular orgnaism
  • Genome analysis indicates a close relationship with animals
  • Have many genes found in animals including genes coding for parts of the signalling pathways
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10
Q

Describe the yeast mating type.

A

Mating type factor = peptide → secretes
Cells from protrusions → for mating → produce haploid spores
Cell signalling → have to recognise the cells

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11
Q

Describe development

A
  • Highly conserved
  • Hierarchical process
  • Starts simple
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12
Q

Describe regulative development.

A
  • 2 cells are able to regulate
  • Divides - ball of cells - mebryo
  • If separate the two halves still form an embryo with the same genetic infomration (no loss)
  • Experiment done with sea urchin
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13
Q

What is gene constancy?

A

Somatic cells generally contain all the same genetic information

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14
Q

What demonstrations that genetic informaiton is not lost during differentaiton?

A

Cloning by transfer of nuclei from differentiated somatic cells

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15
Q

What is an example of cloning

A

Dolly the sheep

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16
Q

What is differential gene expression?

A
  • All cells are derived from the fertilised egg cell
  • Cell lineage restriction is dependent upon differential gene expression
  • Process of development generates different patterns of gene activity in the cells of the embryo
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17
Q

What is gene expression?

A

Process by which a gene codes information converted into the structures present and operating in the cell

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18
Q

Where are proteins regulated?

A

Splicing
Additions/modifications
Transcription
Translation

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19
Q

Describe the eukaryotic gene

A
  • Exon, intron structure (splicing)

- Cis regulatory elements

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20
Q

What are the cis regulatory elements?

A
  • Promoter → upstream → transcription begins

- Regulatory regions → can be distant, upstream or downstream → quite far

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21
Q

What is the role of the cis regulatory elements?

A

key in regulating where and when a gene is transcribed

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22
Q

What are trans-acting factors?

A

Transcription factor proteins - trans regulators - bind directly to DNA or associated with complexes of proteins bound to DNA

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23
Q

Describe RNA polymerase II as a protein coding gene?

A
  • Acts initially at promoter region
  • Unable to transcribe DNA on its own
  • Needs to be associated with proteins
  • Need transcription factors
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24
Q

What is the transcription initiation complex?

A
  • Large complex of proteins
  • Required for the transcription of all protein coding genes transcribe by RNA polymerase
  • Assembly takes place at the TATA box
    Specific sequences of DNA
    In promoter region
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25
Q

What are the functions of the transcription initiation complex?

A
  • Recognize sequence (TATA box binding proteins)
  • Recruit RNA polymerase to promoter
  • Help unwind DNA helix
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26
Q

What are specific transcription factors?

A
  • Enhancers and silencers
  • DNA binding - tissue specific
  • Bind to extended regulatory regions
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27
Q

What are enhancers?

A
  • Bound by transcription factor proteins

- Promote transcription

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28
Q

What are silencers?

A
  • Repressor proteins

- Inhibit transcription

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29
Q

What are DNA binding transcription factors?

A

Recognize and bind to specific sequence of DNA in cis regulatory elements

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30
Q

How big are the binding sites for DNA binding transcription factors?

A

6 -12 bases

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31
Q

What is a protein interaction domain?

A

Binding association with other proteins

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32
Q

What is meant by integration of regulatory information?

A
  • Multiple transcription factors will influence the expression of a gene
  • Cause DNA to loop → bending of DNA structure
  • Allows them to interact with the transcription initiation complex
  • Can contact and alter activity of RNA polymerase II
  • Have multiple
  • Binding of Txn factor 1 to enhancer of gene x activates transcription
  • Factor 2 to enhancer gene y activates transcription factor
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33
Q

What is differential gene expression?

A
  • Combination of cis regulatory element in each gene is different
  • Genes regulated by different transcription factors bound at cis-regulatory element
  • Combinants → which genes expressed
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34
Q

What do RNA polymerase and TF do?

A

Unwind small region of DNA helix at promoter. Use on strand as template

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35
Q

What do TF regulate?

A

Expression of multiple downstreams targets.

Cascade of gene transcription

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36
Q

What can a combination of TF achieve?

A

Regulate multiple - initiate one - cascade - rapidly gene complex patterns

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37
Q

How do cells generate different patterns of gene activity?

A
  • Cells developing communicate with each other
  • Cell signalling
  • Process of development
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38
Q

What happens during the formation of the embryo?

A
  • Cells communicate

- The 2 cells msut be aware of each other

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39
Q

What is the organiser graft experiment?

A
  • Early frog embryos
  • Cells move during development
  • Gastrulation
  • CNS
  • Blastopore
  • Cut and paste in the emrbyo
  • Too the dorsal blastopore lip
  • Put in another embryo which resulted in 2 dorsal blastopore lips
  • You get a double headed frog
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40
Q

What happens during gastrulation?

A

Cells form the gut. They are outside the embryo so have to move inside the embryo

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41
Q

How is the CNS formed in an embryo?

A

Start on the outside of the embryo. Flat sheet of cells which roll up into a tube - move inside the embryo

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42
Q

Describe what happened when they repeated the organiser graft experiment.

A
  1. Dyed the dorsal blastopsore which had been transplanted
  2. Determine which cells in the second body are derived from the host and the donor
  3. Most cells in secondary axis are host derived
  4. Graft produces signals that recruit/organise the host tissue
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43
Q

What can cell signalling do?

A

Regulate gene transcription and expression

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44
Q

What is meant by development?

A

Cell cycle control. Cell movement. Differentiation. Patterning

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45
Q

What is an example of signalling going wrong?

A

A cyclopic lamb - had been eating corn lily. Cyclopamine which inhibits a signalling pathway of development of cells along the midline

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46
Q

What are the different components of a signalling pathway?

A
  • Extracellular signal molecules
  • Receptor protein
  • Intracellular signalling
  • Target proteins
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47
Q

What is the role of the receptor protein in the signalling pathway?

A

allows the cell to perceive that signal

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48
Q

What is the role of the intracellular signalling proteins in the signalling pathway?

A

chain of proteins which pass that signal onn operating within the cell. can be very complicated

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49
Q

What is the role of the target protein in the signalling pathway?

A

Effectors of the signalling pathway.

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50
Q

What kind of signalling molecules transmit over large distances through the extracellular enviornment?

A

Hormones

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51
Q

When is short distance signalling very important?

A

During the developmental process.

Specialisation happens when the embryo is very small

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52
Q

What are some classes of singalling molecules?

A

Peptides. Small molecules eg nitrous oxide. Metabolic products. Lipids

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53
Q

How do receptor proteins work?

A
  • Signals bind to specific receptor proteins
  • High affinity for receptor - binds
  • Signalling molecules present at very low concentrations
  • Cell can only respond to a signal if it has the right receptor
  • Typically present at the cell surface but also within the cell
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54
Q

Describe the signal transduction pathway

A
  • Pass the signal from receptor to targets
  • Can be very complex
  • Contains a series of proteins
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55
Q

What are the main functions of the signal transduction pathway

A
  1. Amplification of the signal
  2. Integration of multiple signalling pathways
  3. Allows levels regulation
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56
Q

How could a signal be amplified?

A

If the receptor proteins have an enzymatic property they can act as a catalyst

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57
Q

How could a signal be integrated?

A

Shared components of different signalling pathways

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58
Q

How could a signal be regulated?

A

Inhibiting, modulating or fine tuning

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59
Q

What happens when the target protein is reached?

A

Changes in the activity of the target proteins which will affect cell behvaiour

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60
Q

Give some examples of altered cellular function

A
  1. Metbabolic = insulin and glucoagon
  2. Cell division = growth factors
  3. Cytoskeleton - axon guidance chemotropic factors (cell movement and cell shape)
  4. Gene expression = growth factors
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61
Q

Describe slime mould as an example of signalling and cell behaviour.

A

Normally = free living unicellular amoebae. Can for coordinated slug like colonies
Regulated by cAMP - move towards and join together

62
Q

Describe how cell signalling affects gene transcription

A
  • Receives the signalling
  • Activated receptor complex
  • Signal transduction pathway
  • Passes signal on to the nucleus
  • Changes the activity of transcription factor proteins in the nucleus
63
Q

Describe how cell signalling affects cell fate.

A
  • Group of cells in the developing embryo
  • produces a signal
  • acts on adjacent cells
  • changes the pattern of gene transcription in those cells
  • some will be encoding addition signalling molecules
  • those signalling molecules can act back or can act on to other cells to change the gene expression
64
Q

Where are hydrophillic molecules found?

A

On the surface membrane

65
Q

Describe the process of hydrophillic signalling moelcules

A
  • Unable to cross plasma membrane
  • Bind to cell surface receptors
  • Activates an intracellular signal transduction pathway
  • Passes signal onto intracellular target proteins
66
Q

What are intracellular receptors?

A

Hydrophobic signalling molecules

67
Q

Describe the process of hydrophobic molecules

A
  • Carried through carrier proteins
  • Pass through plasma membranes
  • Binds with receptor protein in the cytoplasm or nucleus
68
Q

What are the different types of intracellular signalling?

A
  1. Contact dependent/juxtacrine signalling
  2. Endocrine signalling
  3. Paracrine and autocrine signalling
69
Q

What is Contact dependent/juxtacrine signalling?

A
  • Signal may be membrane bound or tightly associated with the extracellular matrix
  • Signal requires direct contact between signalling and responding cell
70
Q

What is Endocrine signalling?

A
  • Hormone signalling eg insulin
  • Produce by an endocrine cell
  • Systemic transport of the signaling molecules to distant cells
71
Q

What is Paracrine and autocrine signalling?

A
  • Signalling that occurs during development
  • Signalling molecules are secreted into the extracellular space
  • Paracrine signal acts on cells neighboring the signalling cell
  • Autocrine signal acts back on the signalling cell → signalling to itself
72
Q

What are molecule switches?

A

proteins involved in the signal transduction pathway

73
Q

Describe protein phosphorylation as a switch.

A
  • Activities of many proteins in signalling pathways are regulated by the removal or addition of phosphate groups
  • Addition or removal of phosphate groups changes the conformation of the proteins
  • Phosphorylation can either activate or inhibit protein function
  • One third of eukaryotic proteins are phosphorylated
74
Q

How do protein kinases work?

A
  • Transfer the terminal phosphate group from ATP to the hydroxyl group of tyrosine, serine or threonine in protein chains
75
Q

Describe protein kinases

A
  • Each cell may contain hundreds of different protein kinases
  • The amino acid sequence of each kinase determines its target specificity
  • Each kinase has many different protein targets
  • Recognize and bind specific target proteins
76
Q

How much of the human genes encode kinases?

A

2%

77
Q

How do protein phosphatases work?

A

Phosphatases catalyse the reverse reaction of removing phosphates groups from tyrosine, serine or threonine residues in phosphorylated proteins

78
Q

What are GTP binding proteins?

A

Guanosine triphosphate binding proteins - class of molecular switch

79
Q

What are the 2 states of GTP binding proteins?

A
  1. Inactive GDP bound form

2. Active GTP bound form

80
Q

What processes are small monomeric GTP binding proteins involved in?

A

Relaying growth factor signalling and regulation

  1. Cytoskeletal behaviour
  2. Growth and cell division
  3. Differentiation
81
Q

What do small monemeric GTP binding proteins do?

A

Active state are able to hydrlyse bound GTP to GDP

82
Q

Describe the intrinsic enzymatic activity of the small monomeric GTP binding proteins.

A

GTPases → able to hydrolyses and remove phosphate group and recycling the molecules back to GDP its inactive form

83
Q

Describe changing GDP to GTP

A

exchanges GDP for GTP → becomes active → in active state is able to pass signal on → intrinsic GTPase activity is stimulated → hydrolysis → phosphate group removed

84
Q

What is required when turning GDP to GTP

A
  • GEF - guanine nucleotide exchange factor → exchanges GDP to GTP
  • GAP protein to stimulate the GTPase
85
Q

What is FGF?

A

Fibroblast growth factor

86
Q

Describe FGF

A
  • Large family of peptide ligands
  • Common structure
  • 22 identified in the human genome
87
Q

WHat are the biological activities of FGF?

A
  1. Regulation of cell growth and survival - don’t act just upon the fibroblast
  2. Regulation of cell differentiation
  3. Regulation of embryonic development
88
Q

What happens if you block FGF in a developing frog embryo?

A

Lose development of all the structures in the posterior

89
Q

What human diseases are FGFs involved in?

A

Skeletal abnormalities (eg dwarfism). Cancer.

90
Q

What type of signal are FGFs?

A

Paracrine or autocrine

91
Q

What do FGFs bind to?

A

Transmembrane receptors

92
Q

Describe FGF being passed into the cell

A
  • Intracellular domain has tyrosine kinase activity (can phosphorylate)
  • Form a complex with extracellular proteoglycans
  • Binding of ligand to receptor causes dimerisation and activation of receptor kinase activity
  • Ligand bind to receptor in extracellular space
  • Brings together 2 receptor molecules
  • Activated receptors phosphorylated tyrosines on various target proteins and autophosphorylate tyrosine residues
  • Signal has now entered the cell
93
Q

Describe the transmembrane protein

A

passes through the plasma membrane → able to insert itself due to the hydrophobic domain

94
Q

Describe receptor activation

A

Immuoglobulin like domains required for ligand binding specificity → extracellular membrane
Intracellular tyrosine kinase domain in the cytoplasm
Bind to cell surface → dimerization → activation of intracellular kinase activity

95
Q

describe passing the signal on adaptor proteins.

A
  • Phosphorylated tyrosine residues on the intracellular domain → act as docking points for addition proteins
    Brings in a whole group of other protein → adaptor proteins → bind to activated receptor complex
    Builds up a complex structure of proteins
    Docking site for adaptor proteins
    Grb2 adaptor protein → binds → acts as a docking site for a GEF aka recruits the GEF to the receptor complex
    A GEF stimulates Ras to cycle to active GTP bound form
    GAP stimulates the GTPase activity of Ras and it cycles back to inactive GDP bound form
96
Q

describe passing the signal on Ras GTPase

A

Activated Ras can pass the signal onto a number of downstream signalling pathways
Ras is a critical regulator of signalling by many growth factors

97
Q

describe mutations in Ras

A

lock into the active GTP bound form are oncogenic and are very common in human cancer → when activated it becomes permanent

98
Q

describe amplification: the MAP cascade

A

The signal is passed on by a cascade of 3 protein kinases
Raf (MAP kinase kinase kinase) is recruited to the inside of the cell membrane by activated Ras
Raf phosphorylates and activates MEK (MAP kinase kinase)
MEK phosphorylates Mitogen Activated Protein Kinase (MAP KInase) also known as Erk (extracellular signal Regulated Kinase)

99
Q

how is Raf recruited?

A

Ras recruited Raf to the inside of the cell membrane
This isn’t a phosphorylation event as Ras is not a kinase simply recruits it
Raf becomes active

100
Q

what happens at the end of the cascade?

A

alters the activity of the proteins for changes in cell behaviour

101
Q

describe MAP kinase as a mediator of FGF signalling

A

Erk (MAP kinase) is phosphorylated and activated within minutes of stimulating a cell with an FGF ligand
Very rapid response
Erk phosphorylates and regulates the activity of multiple proteins including other kinases and regulatory proteins
Erk translocates to the nucleus where it phosphorylates and modulates the activity of multiple transcription factors
Stimulation of this pathway can rapidly lead to changes in gene transcription

102
Q

what experimental data is there looking at FGF signalling

A

Treatment of embryonic cells with FGF rapidly elevates levels of phosphorylated ERK
Treatment with MAP kinase phosphatase inhibits this phosphorylation
Levels of total ERK are unchanged

103
Q

what leads to gene transcription?

A

phosphorylation, activation and translocation

104
Q

what problem does secretion present?

A
  • eukaryotic cell has a compartmentalised structure

- complex system of internal membranes

105
Q

what is the endomembrane system?

A
  • complex system of internal membranes and membrane bound vesicles
  • allows lots of different compartments with complex micro-environments
106
Q

describe the functions of the vesicle transport system?

A
  1. protein secretion and transport
  2. protein processing and degredation
  3. nutrient acquisition
107
Q

what is endocytosis?

A

uptake of extracellular material into membrane bound vesicles

108
Q

what is exocytosis?

A

release of material from membrane bound vesicles to the extracellular space

109
Q

what is protein targeting/sorting?

A
  • specific proteins are required in different compartments

- proteins have peptide motifs

110
Q

what are peptide motifs?

A

enables recognition by cellular machinery and target the proteins to different compartment

111
Q

ehat is the Nuclear Localisation Signal (NLS) ?

A

a sequence of amino acids that targets proteins to be transported from the cytoplasm to the nucleus

112
Q

what typically contain NLS?

A

transcription factors

113
Q

where do proteins for the RER go?

A

either secreted from the cell or to be in the plasma membrane

114
Q

what do secreted proteins usually contain?

A

amino terminal secretory signal sequence

115
Q

what is the amino terminal secretory signal sequence?

A
  • sequence of 20-30
  • have an overall charactersitc
  • contains a core of hydrophobic amino acid
  • allows the protein as its being transported to be inserted into the ER membrane
116
Q

where does translation occur from?

A

a pool of ribosmal subunits

117
Q

how does translation happen?

A
  • individual mRNA is simultaneously being translated by multiple ribosomes
  • forms a polyribosome structure
  • polyribosome floats freely in the cytoplasm
  • if targeted for secretion the polyribosome becomes tethered to the RER
118
Q

describe the mechanism of protein secretion

A
  • Signal peptide recognised by signal recognition particle (SRP)
  • SRP binds to SRP receptor on the external surface of an ER vesicle
  • Protein translocates into the internal lumen via the protein translocator
  • Signal peptide is cleaved by a signal peptidase
  • Protein is trafficked through the ER
119
Q

describe how protein being made gets from the cytoplasm side into the ER lumen

A
  • first thing translated is the amino terminal signal peptide
  • Emerges and is recognised by the signal recognition particle
  • Binds to the signal peptide
  • This halts the translation process
  • Receptor protein present on the outside of the membrane surrounding the ER vesicle → signal recognition particle receptor
  • Binds to the receptor
  • The signal recognition particle is removed
  • Translation of the protein commences again
  • As the protein is made it moves into the lumen of the ER → through the protein translocation → signal peptide is inserted into the membrane → fed into the inside of the vesicle
  • The signal peptide is ultimately removed from the protein chain by signal peptidase
  • In the secreted protein that passes through the ER and the golgi → it is processed
120
Q

what is the golgi apparatus?

A
  • membrane associated with secretory proteins
121
Q

what does the golgi apparatus do?

A

post translational modification

122
Q

describe the role of vesicles in transporting a secretory protein

A
  • fed into the golgi apparatus
  • trafficked to the cell membrane
  • fuse with the cell membrane
  • release their contents
  • either become part of the cell membrane or into the extracellular matrix
123
Q

what are some examples of post translational modification?

A
  • glycolysation
  • protein folding (formation of intra and inter molecule disulphide bonds)
  • attachment of lipid modifications to membrane bound proteins
124
Q

describe glycolysation.

A
  • occurs in RER and golgi
  • enzymes
  • addition of sugar residues to protein chains
  • glycolysiation f secreted proteins is very common
  • glycolysation can stabilise proteins and allow them to fold correctly
125
Q

what are intracellular receptors?

A

hydrophobic signalling molecules

126
Q

describe intracellular receptors

A
  • tend to be products of metabolic pathways
  • have a chain of enzymes which catalyse the formation of these signalling molecules
  • small ad hydrophobic so can pass through the plasma membrane- can move around in solution via carrier proteins
  • at the cell the signal is released and diffuses across the plasma membrane to bind with a receptor protein in the cytoplasm or nucleus
  • to fulfill their function they need to move to the nucleus
127
Q

what are nuclear hormone receptor signal?

A
  • used in signalling by a large group of small of hydrophobic molecules
128
Q

what uses nuclear hormone signalling?

A

steroid hormones, thyroid hormones, retinoic acid and vitamin D

129
Q

what are the benefits of hydrophilic signals?

A

rapidly turned over and degraded in the bloodstream and cellular environment and are used for rapid signalling processes

130
Q

what are the benefits of hydrophobic signals?

A

persist in the body much longer and are involved in long term signalling
- also transcription factors

131
Q

what are some examples of steroid hormones?

A

sex hormones and cortisol

132
Q

describe the features of sex hormones and cortisol.

A

sex hromones = by gonads
cortisol = by adrenal glands
steroid hormones are usually synthesized from cholesterol
act as endocrine hormones
transported systematically in the bloodstream

133
Q

what are the functions of receptor proteins for hydrophobic signalling?

A
  • not only receptors also transcription factors

- means there is no need for molecular switches and changes in gene transcription

134
Q

what happens when the receptor proteins are activated by binding?

A
  • act to regulate directly the transcription of target genes by binding to the cis regulatory elements
135
Q

what happens in the absence of a ligand?

A

receptor is held in an inactive protein complex

136
Q

what does ligand binding lead to?

A

a conformational change in the receptor allowing it to become active and act as a transcription factor

  • can go to the nucleus
  • recognise specific sequences of DNA
  • regulate transcription
137
Q

describe cortisol in signalling

A

In the absence of ligand the receptor is held in an inactive complex in the cytoplasm
In the presence of the ligand the receptor is released from the complex and translocates to the nucleus
Receptor binds signaling molecule → conformational changed
You get dimerisation of the receptor → get 2 active receptors coming together to get a dimer

138
Q

describe retinoic acid in signalling

A

Derivative of vitamin A → involved in multiple processes in animal development eg limb development
In the absence of ligand the receptor is bound to regulatory regions of target genes in the nucleus in association with negative regulators of transcription → co-repressor complex
In the presence of the ligand the receptor dissociates from the inhibitors and associates with activators → co-activator complex

139
Q

what does nuclear hormone signalling elicit?

A

cascades of transcriptional regulation

140
Q

what is the mosaic theory of animal development?

A

cell lineage
restriction is dependent on unequal division of nuclear determinants
during cell division and differentiation

141
Q

what is the principle of nuclear equivalence?

A

during development all cells inherit

the same genetic information

142
Q

what evidence supports the nuclear equivalence during animal development?

A
  • animal cloning experiments
  • nuclear transfer from differentiated somatic cells
  • frog cloning
  • dolly the sheep
143
Q

how do ras protein function as a self regulating molecular switch?

A
  • activated ras, cycles from its inactive GDP bound form to its
    active GTP bound form
  • GTP bound form ras has a
    GTPase activity which rapidly hydrolyses the bound GTP to GDP
  • ras is able to self-regulate its own activity
144
Q

what is Erk?

A

MAP kinase

- can go to the nucleus and phosphorylate transcription factors which then alter gene transcription

145
Q

describe cotisol signalling

A

absence of the
ligand the receptor is held in an inactive complex in the cytoplasm
presence of cortisol the receptor is released from the complex and translocates to the nucleus where it can bind to
DNA and regulate the expression of target genes

146
Q

what are cortisol and RA?

A

not

transcription factors but the ligands that bind to nuclear hormone receptors

147
Q

What are the three main classes of cis-regulatory elements?

A

Promoters, enhancers and silencers

148
Q

what is the function of transcription factors and binding to cis-regulatory regions?

A
  • General transcription factors are components of the transcription initiation
    complex
  • containing RNA pol II
  • RNA polymerase II is unable to transcribe a
    gene on its own
149
Q

how do general transcription factors enable RNA polymerase II to function?

A

TATA box recognition, recruiting RNA pol II and helicase activity

150
Q

describe how trans-acting

factors are able to regulate cell lineage

A
  • egulation of the skeletal
    muscle lineage by myogenic regulatory factors, such as MyoD
  • bHLH transcription factors expressed exclusively in the cells that
    will develop as skeletal muscle
  • activate transcription of
    genes coding for proteins required for muscle development
  • binding as a dimer with
    the E12 protein to E-box sequences in the cis-regulatory of these genes

Cell and Developmental Biology (4 decks)

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