Chapter 1: intro To Molecular Regulation And Signalling Flashcards
1
Q
a developmental process that represents an
amazing integration of increasingly complex
phenomena.
A
Embryology
2
Q
includes investigations of the molecular,
cellular, and structural factors contributing to the
formation of an organism.
A
Embryology
3
Q
Sometimes called organogenesis
A
EMBRYOGENESIS
4
Q
process of progressing from a single cell
through the period of establishing organ primordial
A
EMBRYOGENESIS
5
Q
the first 8 weeks of human development
A
organ primordial
6
Q
the period from embryogenesis until birth
A
time when differentiation continues while the fetus
grows and gains weight.
7
Q
FETAL PERIOD the period from ___ until ___
A
the period from embryogenesis until birth
8
Q
Involves direct embryonic development
A
Genomes
9
Q
Contains all the information required to make an
individual
A
Genomes
10
Q
Information is encoded in DNA in sequences called
____that code for proteins.
A
Genes
11
Q
____regulate expression of other genes and
act as signal molecules to orchestrate
development.
A
Proteins
12
Q
is the basic physical and functional unit of hereditary
A
Genes
13
Q
Human Genome is Made up of approximately 23,000 genes, T/F
A
True
14
Q
A single gene may give rise to many proteins. T/F
A
True
15
Q
Different genes may be transcribed, T/F
A
True
16
Q
DNA transcribed from a gene may be selectively processed to regulate which ___ reach the cytoplasm to become ___
A
RNA
mRNA
17
Q
mRNAs may not beselectively translated, T/F
A
False-may be
18
Q
Proteins made from the ____ may be ____modified
A
mRNAs
Differentially
19
Q
complex of DNA and proteins (mostly histones) where genes are contained
A
Chromatin
20
Q
Chromatin made up of___
A
Nucleosomes
21
Q
basic unit of structure;
A
Nucleosomes
22
Q
Nucleosomes consists of an____ proteins & approximately 140 base pairs of___.
A
octamer of histone
DNA
23
Q
form in which chromatin appears as bead of nucleosomes on a string of DNA
A
Heterochromatin
24
Q
uncoiled state of chromatin
A
Euchromatin
25
DNA regions which can be translated into proteins
exons
26
,interspersed between exons and which are not transcribed into proteins
introns
27
Promoter region that binds____
| for the initiation of transcription
RNA polymerase
28
Translation initiation site to designate the last
| amino acid in the protein, T/F
False-first
29
untranslated region that includes a sequence
| (the poly A addition site) that assists with stabilizing the mRNA
3’
30
Specific parts in the promoter region, where RNA polymerase binds
TATA box
31
A complex of proteins plus an additional protein that is require for binding of RNA polymerase II to the TATA box
Transcription factor
32
Independently folded protein domain that contains at least one structural motif that recognizes double or single-stranded DNA.
DNA-BINDING DOMAIN-
33
Activates or inhibits transcription of the gene whose promoter or enhancer it has bound.
Transactivating domain
34
Regulatory elements of DNA that activate
utilization of promoters to control their efficiency
and the rate of transcription from the promoter
Enhancers
35
Enhancers Can reside on a specific location along the DNA strand. T/F
False- anywhere
36
Enhancers bind transcription factors through ____and are used to regulate the timing of a gene’s expression and its cell specific location
Transactivating domain
37
In which enhancers can inhibit transcription
Silencers
38
DNA Methylation Represses_____
Transcription
39
Methylation of____ bases in the promoter regions of genes represses transcription of genes.
cytosine
40
some genes are silenced by this mechanism.
DNA Methylation
41
responsible for genomic imprinting
DNA Methylation
42
Methylation silences DNA by_____ or by ____and tightly coiled DNA that cannot be transcribed.
inhibiting binding of transcription factors
altering histone binding resulting in stabilization of nucleosomes
43
Also known as Lyonization
X chromosome inactivation
44
One of the X chromosomes in each cell of a female is inactivated
Lyonization
45
phenomena in which only a gene inherited from
father or mother is expressed, whereas the other
gene is silenced.
Genomic imprinting
46
methylation patterns are established during what processes?
spermatogenesis
oogenesis
47
initial transcript of a gene and longer than mRNA because it contains introns that are removed (spliced out)
Nuclear RNA (nRNA) or premessenger RNA
48
The splicing process provides a means for cells to produce single protein from a single gene. T/F
False-different
49
The process of removing different introns and exons in different patterns
Alternative Splicing
50
Proteins derived from the same gene are called
splicing isoforms
51
splicing isoforms also called?
splice variants or alternative variants
52
are formed by interactions between cells and tissues
Organs
53
process wherein one group of cells or tissues causes another set of cells or tissues to change their fate
Induction
54
capacity to respond to such a signal is called
competence
55
requires activation of the responding
| tissue by a competence factor.
competence
56
Many inductive interactions occur between epithelial and
| mesenchymal cells and are called
epithelial—mesenchymal interactions
57
Epithelial cells are joined in tubes or sheet, T/F
True
58
fibroblastic in appearance and dispersed in extracellular matrice
mesenchymal cells
59
In induction, what tissue is the responder
Second tissue
60
In induction, signal are transmitted in ___ direction to complete the differentiation process
Both
61
produce gut-derived organs, including the liver and
| pancreas
gut endoderm and surrounding mesenchyme
62
produce limb outgrowth and differentiation.
limb mesenchyme with overlying ectoderm
63
produce nephrons in the kidney.
endoderm of the ureteric bud and mesenchyme from the metanephric blastemal
64
Type of signal transduction pathways
Paracrine Signaling
| Juxtacrine signalling
65
essential for induction, for conference of competency to respond, and for crosstalk between inducing and responding cells.
Cell-to-cell signaling
66
proteins synthesized by one cell diffuse over short distances to interact with other cells
paracrine interactions,
67
do not involve diffusable proteins.
juxtacrine interactions
68
diffusable proteins responsible for paracrine signaling are called
paracrine factors or growth and differentiation factors (GDFs)
69
Paracrine factors act by Signal transduction pathways either by ?
activating a pathway directly
blocking the activity of an inhibitor of a pathway
70
signaling pathway that transmits information to embryonic cells required for proper cell differentiation
hedgehog signaling
71
Hedgehog signaling is what type of pathway
Paracrine Signaling
72
Signal transduction pathways includes a signaling___ and ___
molecule (the ligand) and a receptor
73
The receptor spans the cell membrane and has an: __, ___, and ___
extracellular domain,
transmembrane domain
cytoplasmic domain.
74
The four groups of GDFs include the
fibroblast growth factor (FGF),
WNT,
hedgehog,
transforming growth factor-B (TGF-B) families
75
type of cell-to-cell signaling that is based on the interaction of noncleaved ligand precursor and the EGFR (Estimated Glomerular Filtration Rate)
Juxtacrine Signaling
76
A protein on one cell surface interacts with a receptor on an adjacent cell in a process analogous to paracrine signaling is what type of pathway
Juxtacrine Signaling
77
The notch pathway is what type of signalling
Juxtacrine
78
In juxtacrine pathway, the Ligands in the _____secreted by one cell interact with their receptors on____ cells.
extracellular matrix
| neighboring
79
the milieu in which cells reside.
extracellular matrix
80
large molecules secreted by cells in the ECM are
collagen, proteoglycans, glycoproteins
81
Proteogylcans
chondroitin sulfates, hyaluronic acid
82
glycoproteins
fibronectins and laminin
83
These molecules provide a substrate for cells on which they can anchor or migrate
Large molecules in the ecm
84
Receptors that link extracellular molecules
Integrins
85
can induce gene expression and regulate differentiation as in the case of chondrocytes that must be linked to the matrix to form cartilage.
integrins
86
direct transmission of signals from one cell to another by
Gap junctions
87
Cell to cell communication is by what pathway
Juxtacrine
88
These junctions occur as channels between cells through which small molecules and ions can pass.
Gap junctions
89
____communication is important in tightly connected cells like epithelia of the gut and neural tube because they allow these cells to act in concert.
Cell to cell
90
Gap junctions are made of
connexin proteins
91
there is a great amount of redundancy built into the process of signal transduction. T/F
True
92
Paracrine Signaling Factors
Fibroblast Growth Factors
Hedgehog Proteins
WNT Proteins
The TGF-B Superfamily
93
FGF proteins produced by these genes activate
tyrosine receptor kinases or fibroblast growth factor receptors (FGFRs)
94
FGFs are particularly important for
angiogenesis, axon growth, and mesoderm different
95
important for development of the limbs and parts of the brain.
FGF8
96
individual FGFs may be responsible for specific developmental events. T/F
True
97
coded for a pattern of bristles on the leg of Drosophila that resembled the shape of a hedgehog.
Hedgehog Proteins
98
In mammals, there are three hedgehog genes
desert,, Indian, and sonic hedgehog.
99
involved in a multitude of events
Sonic hedgehog (SHH)
100
There are at least ___different WNT genes that are related to the segment polarity gene, wingless in Drosophila.
15
101
Their receptors are members of the frizzled family of proteins.
WNT Proteins
102
involved in regulating limb patterning, midbrain development, and some aspects of somite and urogenital differentiation among other actions.
WNT Proteins
103
How many members are TGF-B superfamily
more than 30 members
104
TGF-B superfamily
```
TGF-Bs
the bone morphogenetic proteins (BMPs),
the activin family,
the miillerian inhibiting factor (MIF, anti- miillerian hormone),
and others.
```
105
isolated from virally transformed cells. First member of the family
TGF-BI
106
important for extracellular matrix formation and epithelial branching that occurs in lung, kidney, and salivary gland development.
TGF-B members
107
induces bone formation and is involved in regulating cell division, cell death (apoptosis), and cell migration among other functions.
BMP family
108
Acts as ligands and bind to receptors just as proteins do
neurotransmitters
109
Neurotransmitters are what pathway
Paracrine
110
Neurotransmitter
serotonin, y-amino butyric acid (GABA), epinephrine, and norepinephrine
111
Neurotransmitters provide important signals for embryological development. T/F
True
112
acts as a ligand for a large number of receptors, most of which are G protein— coupled receptors. regulates a variety of cellular functions, including cell proliferation and migration, and is important for establishing laterality, gastrulation, heart development, and other processes during early stages of differentiation.
5HT
113
acts through receptors and appears to play a role in apoptosis (programmed cell death) in the interdigital spaces and in other cell types.
Norepinephrine
114
Master Gene for Embryogenesis
Sonic Hedgehog
115
multitude of signaling molecules that coordinately development,
SHH
116
master morphogen
SHH
117
This protein is involved in development of the vasculature, left—right axis formation, midline, cerebellum, neural patterning, limbs, smooth muscle patterning, heart, gut, pharynx, lungs, pancreas, kidneys, bladder, hair follicles, teeth, thymocytes, inner ear, eyes, and taste buds: a veritable plethora of developmental events.
SHH
118
SHH protein binds to its receptor
Patched (Ptc)
119
protein that normally inhibits the receptor-like protein Smoothened (Smo).
PTc
120
What does SHH upregulate
activity of the GLI family (1 to 3) of transcription factors that control expression of target genes.
121
The specificity of SHH expression in different cell types is regulated by
multiple enhancer elements
122
Before/After translation is SHH cleaved and added cholesterol
After
123
SHH protein is cleaved and cholesterol is
| added to the_____
C-terminus of its N-terminal domain.
124
links SHH to the plasma membrane.
Cholesterol
125
added to the N-terminus and SHH becomes fully functional.
palmitic acid moiety
126
release from the plasma membrane is produced by the
| transmembrane protein
Dispatched
127
regulates the process of convergent extension whereby a tissue becomes longer and narrower.
planar cell polarity (PCP) pathway
128
Convergent Extension Pathway
The Planar Cell Polarity
129
neural tube formation is what key signalling pathway
PCP
130
requires changes in cell shape together with cell movement and intercalation with other cells.
Convergent extension
131
refers to the reorganization of cells and cell sheets in the plane of a tissue, such as occurs during convergent extension.
PCP
132
The principal PCP signaling pathway is the
WNT pathway,
133
WNT pathway receptor
Frizzled (Fz)
134
two other transmembrane protein of WNT
Celsr and Vangl.
135
These transmembrane proteins VANGL & CELSR primarily target activation of ______
DISHEVELLED (DVL)
136
Ways that transmembrane chons (vangl and celsr) target DVL
directly or through downstream effectors,
137
Downstream effectors
Prickle (Pk) and Diego (Dgo)
138
___regulates signaling via the ___ & ___ kinases to upregulate_____.
DVL
Rho and Rac
c-Iun N-terminal kinases (INK)
139
that control cytoskeletal changes and other downstream eifectors including transcription factors.
c-Iun N-terminal kinases (INK)
140
bind to transmembrane ligands of the DSL (Delta/Serrate/LAG-2) family
Notch transmembrane receptors
141
Notch transmembrane receptors requires ______ for signaling to occur.
cell-to-cell contact (juxtacrine signaling
142
How many notch fam members in mammals and transmembrane ligand
4 notch
| 5 transmembrane
143
Transmembrane ligands are
lagged 1 and 2 and Delta 1 to 3
144
Binding of one of these notch proteins to a Notch receptor causes a_______ in the Notch protein such that part of it on the _____side of the membrane is_____.
conformational change
cytoplasmic
cleaved
145
Notch pathway involves secondary messenger, T/F
False- no involvement
146
In notch pathway, the cleaved portion of the protein enters the nucleus____ and binds to a_____ that normally represses transcription of Notch target genes.
directly
DNA- binding protein
147
Binding of Notch to DNA binding protein removes the____ activity of the repressor and permits activation of_____
inhibitory
downstream genes.
148
involved in cell proliferation, apoptosis, and epithelial to mesenchymaltransitions.
Notch signaling
149
especially important in neuronal differentiation, blood vessel formation and specification (angiogenesis), somite segmentation, pancreatic B-cell development, B- and T-cell differentiation in the immune system, development of inner ear hair cells, and septation of the outflow tract of the heart.
Notch signaling
150
Mutations in JAG1 or NOTCH2 cause____
Alagille syndrome
151
characterized by cardiac outflow tract defects as well as skeletal, ocular, renal, and hepatic abnormalities.
Alagille syndrome
152
have also been linked to cases of tetralogy of Fallot (a cardiac outflow tract defect).
JAG1 mutations
