BIO 310 Study Guide - Midterm Guide: Wee1, G1 Phase, Cdc20
Document Summary
M-cdk must be degraded to start g1. S-cyclin is synthesized for s-phase entry and degraded to complete s phase. T-loop moves and opens up access to active site. Wee1 kinase phosphorylates cdk to prevent complex from moving on in cell cycle. Cdc25 phosphatase (undoes wee1 kinase by removing inhibitory phosphate) Cki (bind to active site to prevent cyclin-cdk complex from forming. Apc (binds to cdc20 to ubiquitinated and degrade cyclin-cdk complex) Tyrosine kinase binds to receptor to activate pathway. Ras begins cascade by activating mapk, beginning the immediate early response. Activate myc to transcribe genes needed for activating g1-cdk. G1 cyclin are transcribed after the mitogenic signal to start dividing. Cdk phosphorylates rb, causing it to dissociate from e2f. Role of rb is to bind and inhibit transcription factor for the genes needed for s-phase entry. E2f turns on genes needed for s-phase entry. Dna replication during g1, proteins assemble at the origin of replication.
