Question

13. Within the "Cell Cycle Regulators and Cancer" section, click on the "stop sign" inhibitory symbol in G1 phase of the cell cycle diagram. a. The p53 and Rb genes are proto-oncogenes/tumor suppressors (highlight one of the two preceding terms). Justify your choice in 1-3 sentences by describing the functions of the proteins encoded by these genes. Justification: b. Why do we consider potentially cancer-causing mutations in these genes to be recessive? Response: c. Under what circumstances do we consider potentially cancer-causing mutations to be dominant? Response:

Answer 1

Loctivated p53 protein act as transcription factor (от 2" ene, bawi ( Ш. ps3 деле је Responside. for p21 gene's protein syntheoso when p21 genes prorein synthesis completed than p21 protein Bind with Wils- COK and S-LDK ( cyclin - cyclin Dependent kiname) and result is an arrest The cell cycle In , phase so bith gene'o are antitomas. db are yde 6 some childern with hereditary retinoblastoma Inherit a single defective copy Of The RB gene some time seen as a small deletion on chromosome 13 They develop retinal tumor early in life and genearlly in both eye . Each tumor that contain about 4x107 celw but only about I in lot Cells actually gives rise to a tumor cell This tinding shows that the defective RB allele on is aching as recessively at the Cell was devel. E le i Ano proto-oncogeneo have potential to convert in to cances Cello when a mutation ocuro The gene Than gene panamanatly become turn on so This is called gain of function mutation mutations are also considered dominant mutation in Dee

Anawen (13) + Ans.(a ps3 and Rb gene one pooto-oncogenen / Tumore suppressoro. Reson and function of the protein encoded by the gene : - Rb gene Codes protein called messi "pRb" . it is tumor suppressor gene. Joss of Funchion mutations in Rb gene are a Brociated with The Retinoblastomo. pRb protein are helpfule in controling of Elf activity. Here E2f protein are useful in progression of cell cyce from is, to s phase if prb protein's affinity to bind i with Elf protein then cell cycle not proced into from no to s phase after Phospharilation of pRb jt affinity to bind Elf Reduce so cell cycle proced in next phase. D. CDK 4/6 are responsity of phosphorylation of prb protein in eonly use phe ③ p53 gene so 19 go a a I ps3 mom 2 protein , moma protein Cellular atrena p53 protein like DNA damage ® p53 protein become activate because it iu how phosphorylation phonphonylated by Kinone Engine In phosphorylation