Cell Signalling Flashcards
why is protein phosphorylation central to cell signalling?
as phosphates are negatively at cellular pH they can change the charge on amino acids which can then interact with positively charged amino acids on other proteins.
simplest way to change transcription?
steroid hormones.
How does the activation of PKC differ from PKA?
activated by two messengers DAG and Ca2+ rather than one (cAMP).
How is CaMK activated?
by the binding of four Ca2+ (i.e. lots required acting as a threshold).
what is Ras GEF do?
releases GDP on Ras so it can bind to GTP i.e. it is a GTP/GDP exchange factor.
what does Ras-GTP do?
activates RAF (kinase).
what are the two different roles of TGF-beta and EGF?
T - involved in differentiation.
E - growth factor inducing cells to enter cell cycle.
Describe paracrine signalling.
p signals released by cells into extracellular fluid in neighbourhood and act LOCALLY.
what do the series of intermediates in the protein kinase cascades allow?
AMPLIFICATION.
which three amino acid residues are important in cell signalling?
serine, threonine, tyrosine.
what are GAPs?
GTPase activating proteins - stimulate intrinsic GTPase activity of Ras.
which two transcription factors are required for fos mRNA expression?
serum response factor
ternary complex factor.
what does TGF-beta induce the transcription of?
fibroblasts
collagen
