CellSig5 - 19 Flashcards Preview

Y2S2 - Cell Signalling > CellSig5 - 19 > Flashcards

Flashcards in CellSig5 - 19 Deck (19):
1

What generally activates proteins?

Addition of phosphate groups

2

What catalyses dephosphorylation?

Phosphatase

3

What are the general kinase targets?

Sugars, nucleic acids, lipids, proteins

4

Where does protein phosphyrlation usually occur?

On amino acids with hydroxyl-containing side chains, either serine/threonine or tyrosine

5

What part of phosphorylation is actively regulated?

Turning on by kinases

6

How is the addition of phosphate groups visualised?

Addition of gamma-32-p-ATP, then use of radiation counter or autoradiography

7

What secondary messengers are controlled by Ca?

MLCK - myosin light chain kinase

8

What secondary messengers are controlled by nucleotides?

cAMP/cGMP-dependent kinase (PKA/PKG, or A/G kinase)

9

What secondary messengers are controlled by lipids?

Protein kinase B (PKB aka Akt) or C (PKC requires Ca)

10

What controls secondary messengers?

Ca, nucleotides, lipids

11

What controls phosphorylation?

MAPKs - mitogen activated protein kinases

12

What controls autophosphorylation?

TGFb signalling

13

What is a consensus phosphorylation site?

The only context in which any Ser, Thr or Tyr residue can be phosphrylated

14

Outline regulation of cell cycle

Cdk1 + M-cyclin > inactive M-Cdk + Cdk-activating kinase + Cdk-inhibitory kinase > inactive M-Cdk + pCdc25 > active M-Cdk

15

Outline feedback of the regulation of cell cycle

Active M-Cdk promotes Cdc25 phosphorylation and inhibits Cdk-inhibitory kinase

16

Characterse cell cycle regulation feedback

Positive feedback

17

Outline the vertebrate ERK-MAP kinase cascade

Grb2 > SOS > Ras > Raf > ERK > multiple substrates

18

What do scaffold proteins do?

Spatially regulate kinase cascades to prevent cross-talk (some kinases are used in multiple cascades)

19

Characterise phosphatases

Broader substrate specificity than kinases and are probably not as tightly regulated as kinases