VPY-0052
QUESTION
The catalytic subunit of protein kinase A, released when cAMP level rise, enters the nucleus and phosphorylates a nuclear protein called?
OPTIONS
(A) SRA
(B) siRNA
(C) CREB
(D) CRE
ANSWER
(C) CREB
EXPLANATION
CREB is the correct option because protein kinase A activated by cAMP can enter the nucleus and phosphorylate cAMP response element-binding protein (CREB), which regulates transcription of target genes. SRA, siRNA and CRE do not represent the nuclear protein phosphorylated by PKA in this pathway; CRE is a DNA regulatory element rather than a protein.