Faculty Collaboration Database

Protein kinase A induces phosphorylation of the human 5-HT1A receptor and augments its desensitization by protein kinase C in CHO-K1 cells. Biochemistry 1994 Sep 20;33(37):11264-9

Date

09/20/1994

Pubmed ID

7727377

DOI

10.1021/bi00203a023

Scopus ID

2-s2.0-0027936264 (requires institutional sign-in at Scopus site)   26 Citations

Abstract

Protein kinase C has been previously shown both to phosphorylate and to desensitize the ability of the human 5-HT1A receptor to inhibit adenylyl cyclase [Raymond, J. R. (1991) J. Biol. Chem. 266, 14747-14753]. In this study, we examined the effects of short-term treatment with protein kinase A activators on coupling to the inhibition of adenylyl cyclase and on phosphorylation of the human serotonin 5-HT1A receptor in CHO cells that stably express 1200 fmol of receptor/mg of protein. Forskolin induced a concentration- and time-dependent phosphorylation of the receptor that was detectable at 5 min and maximal at 15-30 min with a half-maximal concentration of 10-20 microM. Phosphorylation was also induced by Sp-cAMPS or dibutyryl-cAMP, and blocked by Rp-cAMPS and a pseudosubstrate inhibitor of PKA, but not by heparin (inhibitor of receptor kinase) or sphingosine (inhibitor of PKC). The stoichiometry of phosphorylation induced by forskolin was 1 mol of phosphate per mole of receptor. PKA activators did not induce a measurable desensitization of 5-HT1A receptor-inhibited adenylyl cyclase activity. However, forskolin augmented the desensitization caused by a submaximal concentration of phorbol 12-myristate 13-acetate (300 nM PMA) as evidenced by a rightward shift of the concentration-response curve for 5-HT, and approximately doubled the amount of phosphate incorporated into the receptor by PMA. Forskolin did not augment desensitization or increase the degree of phosphorylation induced by a maximal concentration of PMA (5 microM).(ABSTRACT TRUNCATED AT 250 WORDS)

Author List

Raymond JR, Olsen CL

Author

John R. Raymond MD President Emeritus MCW, Professor in the President department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Adenylyl Cyclases
Animals
CHO Cells
Cell Membrane
Colforsin
Cricetinae
Cyclic AMP
Cyclic AMP-Dependent Protein Kinases
Heparin
Humans
Kinetics
Phosphorylation
Protein Kinase C
Receptors, Serotonin
Receptors, Serotonin, 5-HT1
Recombinant Proteins
Sphingosine
Tetradecanoylphorbol Acetate
Thionucleotides
Transfection