BIOL 2020 Lecture 7: 7.Cellular Reproduction
31 Aug 2016
School
Department
Course
Professor
Document Summary
Cell fusion = take cells at different stages of the cycle and fuse plasma membranes together cytoplasm mixes. Fuse: g1 + s phase dna from the g1 starts to replicate right away diffusible factor initiates s phase. Fuse: g1 + m phase dna in g1 cell starts to compact inside the nucleus as if ready to undergo division = premature chromosomal compaction. Maturation promoting factor (mpf) - protein that initiates entry of cell into m phase; has kinase activity and cyclin. Cyclin-dependent kinases (cdks) = mpf-like enzymes that phosphorylate proteins throughout the cell cycle. Regulation of cell cycle - passage of cell through checkpoints (start + g2-m transition) requires activation of cdc2 kinase (s. pombe - fission yeast) by g1/s or mitotic cyclin; exit mitosis triggered by drop in mitotic cyclins. 1. cdc2 kinase is inactive with thr 161 + tyr 15 attached. Wild type: normal size until after m when get smaller.
