BIO 201 Lecture Notes - Lecture 26: Gtpase, Dna Replication, Conformational Change
13 Apr 2017
School
Department
Course
Professor
Document Summary
Control mechanisms used by eukaryotic cells to ensure cell proliferate only when internal and external conditions are met. Regulated by many different sentinel systems monitor nutrients, growth factors, cell size, dna damage, tension. Cells don"t divide until it"s big enough that daughter cells are big enough to survive. Aka the point of no return for proliferation. Can lead to excessive proliferation of cells cancer. Tumor suppressor genes - rb and p53. Proto-oncogenes - ras (mutations in genes encoding proteins that are proliferation promoting genes) Genes whose normal protein products act to prevent cell cycle progression. Causes progression through cell cycle at inappropriate times. Rb is also the name of the protein product. Rb protein prevents cells from entering s phase (g1/s checkpoint) Unstimulated, rb binds to transcription factor e2f. Growth factor ras pathway (kinase cascade) cdk-cyclin phosphorylates. Rb rb conformational change doesn"t sit on e2f. E2f does gene transcription translation proteins involved in dna replication.
