Proto-oncogene Sno expression, alternative isoforms and immediate early serum response.
The mouse Sno gene, a Ski proto-oncogene homolog, expresses two isoforms, SnoN and SnoN2 (also called sno -dE3), which differ from each other in a location downstream from the site of alternative splicing previously described in the human SNO gene. SnoN2 is missing a 138 nt coding segment present in mouse SnoN and human SNON . We have cloned and sequenced the human ortholog of mouse SnoN2 , the existence of which was predicted from conservation of the alternative splice donor site that produces the SnoN2 isoform. Mouse SnoN2 and SnoN are expressed throughout embryonic development, in neonatal muscle and in many adult tissues. SnoN2 is the major species in most tissues, but SnoN and SnoN2 are expressed at approximately equal levels in brain. In human tissues, SNON2 is the less abundantly expressed isoform. Expression of mouse SnoN and SnoN2 mRNAs is induced with immediate early kinetics upon serum stimulation of quiescent fibroblasts, even in the presence of the protein synthesis inhibitor cycloheximide, while Ski is not. Interestingly, although both isoforms of Sno are induced, SnoN2 induction is much higher than SnoN . These data are consistent with a role for Sno in the response to proliferation stimuli.
Pearson-White
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Department of Microbiology, Box 441, University of Virginia Medical Center, Charlottesville, VA 22908, USA. sp3i@virginia.edu
Crittenden
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D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D003001:Cloning, Molecular; D005091:Exons; D015870:Gene Expression; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D051379:Mice; D008969:Molecular Sequence Data; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins / Q000235:genetics*; D017386:Sequence Homology, Amino Acid; D012710:Serum Albumin, Bovine
D047908:Intracellular Signaling Peptides and Proteins; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; D011518:Proto-Oncogene Proteins; C060615:SKIL protein, human; C486157:Skil protein, mouse; D012710:Serum Albumin, Bovine