Question

Question 1

Loss-of-function mutations in the CCR5 gene have been linked to resistance to HIV infection. As a researcher you are interested in using CRISPR to provide protection against HIV. Provide a brief overview of the steps you would take to use CRISPR target the CCR5 gene in order to give someone resistance to HIV. Be sure to identify the main biochemical components, their function, and the cellular processes directly involved.

Question 2:

Answer 1

2. Four CDKs(2,3,4&6) acts in early G1. All four associate with the D cyclins which are synthesized early in G1 in a growth factor dependent manner. CDK 4 and CDK6 play the principle roles in the regulation of downstream events. The only known target of these early CDK- Cyclin complexes is the retinoblastoma protein RB-1, Which is a negative regulator of the cell cycle. RB1 in its unphosphorylated form binds transcription factors of E2F family which normally activate genes required for entry of S phase. RB-1 inhibits the expression of theses genes in two ways: by sequestering the E2F activation domain, and direct repression by chromatin remodeling. Phosphorylation of RB-1 by the early G1 CDK-D Cyclin complexes releases the repression.

Mutations in the RB1 gene disrupt the structure and function of the pRB protein leading to deregulation of cell proliferation