Multiple Choice
Which of the following statements about protein kinase A (PKA) is false?
12. Biosignaling
cAMP & PKA
Struggling with Biochemistry?
Join thousands of students who trust us to help them ace their exams!Watch the first videoMultiple Choice
What could be the result of a mutation in the R subunits of cAMP-dependent protein kinase A (PKA) that inhibits formation of the R2C2 protein complex?
A
PKA will always remain in the inactive state.
B
cAMP would drastically decrease PKA activity.
C
PKA will always remain in the active state.
D
No effective change occurs.
Verified step by step guidance1
Understand the structure of cAMP-dependent protein kinase A (PKA), which consists of regulatory (R) and catalytic (C) subunits forming an R2C2 complex in its inactive state.
Recognize that the binding of cyclic AMP (cAMP) to the regulatory subunits causes a conformational change, releasing the catalytic subunits and activating PKA.
Consider the effect of a mutation in the R subunits that inhibits the formation of the R2C2 complex. This would prevent the regulatory subunits from binding to the catalytic subunits.
Without the formation of the R2C2 complex, the catalytic subunits would not be inhibited by the regulatory subunits, leading to a constitutively active state of PKA.
Conclude that the mutation would result in PKA always remaining in the active state, as the regulatory subunits cannot bind and inhibit the catalytic subunits.
Related Videos
Related Practice
