Direct link to image httpss28postimgorgdpw9xlpv1imagepng Whi

Direct link to image: https://s28.postimg.org/dpw9xlpv1/image.png

Which of the following could most quickly reverse calmodulin activity? ADP A plasma membrane voltage gated sodium ion channel. A plasma membrane calcium ion pump. GTP A plasma membrane potassium ion channel. Which of the following could decrease signaling via phospholipase C? Release of Ca2+ into the cytosol. Phosphorylation of IP3. Synthesis of DAG. Opening of TRP Ca2+ channels. Phosphorylation of PKC. Which of the following could be used to demonstrate the principle of co-incidence detection in a signaling pathway? Activity of the androgen receptor at both cytoplasmic leaflet of the plasma membrane and within the nucleus. Activation of PKC at the plasma membrane by Ca2+ and DAG. Binding of GDP or GTP to a heterotrimeric GTPase. Reassociation of subunits of PKA. Binding of Ca2+ to the ER lumeanal domain of STIM1. Match the correct(a) target tissue, (b) hormone and (c) major response. Heart, adrenaline, decreased heart rate. Smooth muscle, vasopressin, amylase secretion. Kidney, parathormone, bone resorption. Ovary luteinizing hormone, estrogen secretion. Adrenal cortex, adrenocorticotrophic, hormone, secretion of cortisol. Which best describes how second messengers convey messages? An increase in their steady-state concentration. A decrease in their steady-state concentration. By diffusing through the cytosol only. By A and C. By a change in their steady-state concentration.

Solution

5.Ans- The plasma membrane calcium ion pump

Explanation-

Calmodulin regulates membrane association of many intracellular proteins (19-21), and it has been observed that RGS proteins associate with the inner surface of the plasma membrane (22-25)

A potential mechanism for feedback regulation of G protein-mediated Ca²⁺signaling was suggested by the observation that PIP₃-dependent inhibition of GAP activity was reversed by Ca²⁺/calmodulin. The concerted action of Ca²⁺/calmodulin and PIP₃ may regulate RGS GAP activity to initiate [Ca²⁺]i oscillations evoked by G protein-coupled agonists..