In sea urchin, the acrosome reaction has 2 components:

1. Exocytosis

2. Extension of the acrosomal process

TLS Online TPP Program

#Id: 1134

#Unit 2. Cellular Organization

CDK- Cyclin in Yeast-

G1 cyclin gene - CLN3

G1/S phase cyclin genes - CLN1 and CLN2

TLS Online TPP Program

#Id: 1135

#Unit 2. Cellular Organization

Kinase in cell cycle-

CAK kinase- Activate CDKs

Wee1 kinase- Inhibit CDKs

TLS Online TPP Program

#Id: 1136

#Unit 2. Cellular Organization

Phosphatase in cell cycle-

Cdc25 phosphatase Activates CDKs

Cdc14 phosphatase Activates Cdh1 to degrade mitotic cyclins

TLS Online TPP Program

#Id: 1137

#Unit 2. Cellular Organization

Phosphatase in cell cycle-

Cdc25A phosphatase Activates vertebrate S phase CDKs

Cdc25C phosphatase Activates vertebrate mitotic CDKs

TLS Online TPP Program

#Id: 1138

#Unit 2. Cellular Organization

Inhibitory Proteins in Cell Cycle-

Sic1 - Binds and inhibits S phase CDKs

CKIs p27, p57, and p21- Bind and inhibit CDKs

INK4 - Binds and inhibits G1 CDKs

Rb - Binds E2Fs

TLS Online TPP Program

#Id: 1139

#Unit 2. Cellular Organization

Ubiquitin-Protein Ligases-

SCF- Degradation of phosphorylated Sic1