Characterization of conserved tandem donor sites and intronic motifs required for alternative splicing in corticosteroid receptor genes.
Alternative splicing events from tandem donor sites result in mRNA variants coding for additional amino acids in the DNA binding domain of both the glucocorticoid (GR) and mineralocorticoid (MR) receptors. We now show that expression of both splice variants is extensively conserved in mammalian species, providing strong evidence for their functional significance. An exception to the conservation of the MR tandem splice site (an A at position +5 of the MR+12 donor site in the mouse) was predicted to decrease U1 small nuclear RNA binding. In accord with this prediction, we were unable to detect the MR+12 variant in this species. The one exception to the conservation of the GR tandem splice site, an A at position +3 of the platypus GRgamma donor site that was predicted to enhance binding of U1 snRNA, was unexpectedly associated with decreased expression of the variant from the endogenous gene as well as a minigene. An intronic pyrimidine motif present in both GR and MR genes was found to be critical for usage of the downstream donor site, and overexpression of TIA1/TIAL1 RNA binding proteins, which are known to bind such motifs, led to a marked increase in the proportion of GRgamma and MR+12. These results provide striking evidence for conservation of a complex splicing mechanism that involves processes other than stochastic spliceosome binding and identify a mechanism that would allow regulation of variant expression.
Rivers
Caroline
C
Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom.
Flynn
Andrea
A
Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom.
Qian
Xiaoxiao
X
Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom.
Matthews
Laura
L
Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom.
Lightman
Stafford
S
Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom.
Ray
David
D
Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom.
Norman
Michael
M
Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology (C.R., A.F., X.Q., S.L., M.N.), University of Bristol, Bristol BS1 3NY, United Kingdom; and Endocrine Sciences Research Group (L.M., D.R.), University of Manchester, Manchester Academic Health Sciences Centre, Manchester M13 PT, United Kingdom.
D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017124:Conserved Sequence; D005091:Exons; D006801:Humans; D007438:Introns; D008322:Mammals / Q000235:genetics*; D011485:Protein Binding; D022821:RNA Splice Sites; D012342:RNA, Small Nuclear / Q000235:genetics / Q000378:metabolism; D018161:Receptors, Mineralocorticoid / Q000737:chemistry / Q000235:genetics; D011987:Receptors, Steroid / Q000737:chemistry / Q000235:genetics*; D016415:Sequence Alignment
D022821:RNA Splice Sites; D012342:RNA, Small Nuclear; D018161:Receptors, Mineralocorticoid; D011987:Receptors, Steroid; C405483:U1 small nuclear RNA