Cell Signaling Flashcards
Cells in the embryo do not have a circulatory system to transport communication, so what do they have?
Local Mediators that include growth factors.
Ligands
signaling molecules latin (to bind)
Signal Transduction
responses to ligand binding, including second messengers
Three types of signal transduction
Diffusion, Signals in ECM when touching, and just simple touching
What do growth factors do?
encode proteins, short range, cells respond by dividing or differentiating
What is a kinase?
They catalyze the addition of phosphates
Cell Signaling: Ca2+ and IP3 Pathway
First messenger converts G protein to Phosphorylase C, which cleaves PIP2 into IP3 which activates Ca2+ channels in the endoplasmic reticulum to open, releasing calcium and signaling other cellular responses.
Which parts of signal transduction is necessary to memorize?
ligand, receptor, main signal intermediate, nuclear factor
Receptor Tyrosine Kinase
Ligand - growth factor fibroblast growth factor FGF and epidermal growth factor EGF
Receptor: Tyrosine Kinase
Intermediate: Ras
Nucleus: active phosphorylated transcription factor
What can fibroblast growth factor FGF do?
Give long hair
Cell Signaling: TGF Beta Pathway
Ligand: growth factor (e.g: TGF beta and BMP)
Receptor: serine/threonine kinase
Intermediate: Smad
Nucleus: phosphorylated Smad for transcription or repression
What can TGF beta do?
Give cows huge muscles
Cell Signaling: Wnts
Ligand: Wnt
Receptor: Frizzled
Intermediate: B-catenin
Nucleus: B catenin and TCF
What is special about Wnts pathway?
It is an example of where the signaling stops a process that is usual, B catenin is no longer destroyed and can combine with TCF to change gene expression
Planar Cell Polarity (PCP)
Ligand: Wnt, or cell adhesion proteins
Receptor: Frizzled or Strabismus (van gogh)
Intermediate: Disheveled and friends
Effect: Changes in actin
