IP3 triggers the opening of IP3-gated Ca²+ channels in the ER and elevation of cytosolic free Ca²+.

TLS Online TPP Program

#Id: 8612

#XL - T Zoology

Phosphorylation of a critical threonine residue in the activation loop, Thr-160, allowing substrates to access the active site of the CDK

TLS Online TPP Program

#Id: 8613

#XL - T Zoology

Threonine -160 phosphorylation is mediated by 

CDK-activating kinase (CAK)

TLS Online TPP Program

#Id: 8614

#XL - T Zoology

Two inhibitory phosphorylations on CDK play a critical role in controlling CDK activity:

Y15

T14

TLS Online TPP Program

#Id: 8615

#XL - T Zoology

Y15 & T14 are situated in the G-loop of the CDK, containing the consensus sequence GEGT14Y15GVV

TLS Online TPP Program

#Id: 8616

#XL - T Zoology

Phosphorylation of T14 and Y15 in this G-loop

introduces negative charge that electrostatically interferes with the binding of ATP in the catalytic pocket.

TLS Online TPP Program

#Id: 8617

#XL - T Zoology

Wee1 kinase Inhibits CDKs in all organisms