BIO SCI 93 Lecture Notes - Lecture 18: Spindle Apparatus, Dna Replication, Nuclear Membrane

• School: UC-Irvine
• Department: Biological Sciences
• Course: BIO SCI 93
• Professor: Busciglio/ Wood/ Green

Document Summary

Sister chromatids would fail to separate during anaphase. Checkpoints are critical control points where stop and go signals regulate cell cycle. If cell doesn"t get repaired: cell gets sent to g0, if unable to repair, cell dies. Protein kinases: give go-ahead signals at g1 and g2 checkpoints, protein kinases must be attached to cyclin in order to be active, thus known as cyclin-dependent kinases. Cdk is always present: as cyclin degrades, mpf activity decreases. Mpf promotes mitosis: mpf kinase being involved in degrading nuclear envelope, condensation of chromosomes, and aspects of mitotic spindle. Cdk4/6, cyclin d: signaling is key, removes inhibition of gene expression. Loses these two aspects of normal cells: anchorage dependence: cells require surface for division, density-dependent inhibition: cells form a single layer. Gene with potential to cause cancer but that requires some alteration to become an oncogene. Mutations can convert a proto-oncogene into an oncogene.