Angiotensin II type-1 receptor subtype cDNAs: differential tissue expression and hormonal regulation.
A rat angiotensin, type 1A (AT1A) receptor cDNA was cloned recently and shown to be a member of the 7-transmembrane, G-protein coupled family of receptors. Here, we report the cloning, sequencing, and expression of a previously unsuspected second form of the type 1 receptor (AT1B) in the rat which exhibits high similarity with the AT1A receptor relative to amino acid sequence (95% identity), binding of angiotensin II analogs, and utilization of Ca+2 as its intracellular second messenger. The adrenal and pituitary gland express primarily AT1B mRNA whereas vascular smooth muscle and lung express primarily AT1A mRNA. Estrogen treatment suppressed AT1B but not AT1A mRNA levels in the pituitary gland. Thus, the unexpected existence of two putative AT1 receptor genes appears to be related to the differential regulation of their expression rather than to different functional properties of the encoded receptor proteins.
Kakar
S S
SS
Department of Physiology and Biophysics, University of Alabama, Birmingham 35294.
Sellers
J C
JC
Devor
D C
DC
Musgrove
L C
LC
Neill
J D
JD
D000595:Amino Acid Sequence; D000804:Angiotensin II / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D002118:Calcium / Q000378:metabolism; D002478:Cells, Cultured; D003001:Cloning, Molecular; D004277:DNA, Single-Stranded; D004967:Estrogens / Q000494:pharmacology; D005260:Female; D005786:Gene Expression Regulation; D012739:Gonadal Steroid Hormones / Q000494:pharmacology*; D008969:Molecular Sequence Data; D010903:Pituitary Gland, Anterior / Q000737:chemistry* / Q000187:drug effects; D011374:Progesterone / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D011945:Receptors, Angiotensin / Q000032:analysis / Q000145:classification / Q000187:drug effects / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D014018:Tissue Distribution; D014162:Transfection
D004277:DNA, Single-Stranded; D004967:Estrogens; D012739:Gonadal Steroid Hormones; D012333:RNA, Messenger; D011945:Receptors, Angiotensin; D000804:Angiotensin II; D011374:Progesterone; D002118:Calcium