Regulation of corticotropin-releasing hormone type 2 receptors by multiple promoters and alternative splicing: identification of multiple splice variants.
We demonstrate that multiple promoters and alternate splicing regulate expression of the human CRH receptor type 2 (CRHR2) gene. We show that flanking regions to the first exons drive promoter activity in both endogenously and nonendogenously expressing cell lines. Putative promoter elements have been identified that are conserved between species, including the comparison of CRHR2gamma in nonhuman primates that was previously known only in humans, which may be responsible for subtype tissue specific regulation. We have identified novel transcripts produced by alternate splicing of the first exon of CRHR2beta (beta1a) with various combinations of the 5' exons including a novel exon (beta1c) spliced to the common exons. The 5' structure of the gene permits many other combinations of alternate splicing that may arise as part of a regulatory mechanism controlling functional receptor expression. The 5'-untranslated region of the first exons has been extended; and 3' acceptor sites identified within the 5' untranslated region of CRHR2gamma and CRHR2alpha are used during alternate splicing of CRHR2beta upstream exons. This has important implications because various reports on the expression of CRHR2gamma and CRHR2alpha have been unable to discriminate between the functional receptor and CRHR2beta alternate splice variants. Only the described sequences upstream of the 3' splice site are unique to CRHR2gamma and CRHR2alpha.
Catalano
Rob D
RD
Department of Pathology, University of Cambridge, Cambridge CB2 1QP, United Kingdom.
Kyriakou
Theodosios
T
Chen
Jing
J
Easton
Andrew
A
Hillhouse
Edward W
EW
D020121:5' Untranslated Regions / Q000235:genetics / Q000502:physiology; D017398:Alternative Splicing / Q000235:genetics* / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004847:Epithelial Cells; D005091:Exons / Q000235:genetics / Q000502:physiology; D005786:Gene Expression Regulation / Q000235:genetics* / Q000502:physiology; D006801:Humans; D008969:Molecular Sequence Data; D002679:Pan troglodytes; D010215:Papio; D011401:Promoter Regions, Genetic / Q000235:genetics / Q000502:physiology; D019105:Random Amplified Polymorphic DNA Technique; D018019:Receptors, Corticotropin-Releasing Hormone / Q000235:genetics* / Q000502:physiology; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014162:Transfection
D020121:5' Untranslated Regions; C101531:CRF receptor type 2; D018019:Receptors, Corticotropin-Releasing Hormone