Abstract
Evidence for the alternative splicing of the message for mouse pseudouridine synthase 1 (mPus1p) was found when several expressed sequence tag clones were completely sequenced. The genomic DNA for the MPUS1 gene (6.9 kb) was cloned from a mouse genomic library; the gene contains seven exons, of which three are alternatively spliced. In addition, one of the internal exons (exon VI) is unusually large. RNase protection analysis confirmed that several alternatively spliced messages were present in mouse tissues and cells in culture. A Western blot of total cellular protein from mouse tissues and cultured cells was reacted with an antibody specific for mPus1p; at least three proteins were detected. One protein corresponds to the predicted molecular mass of mPus1p (44 kDa) and is the most abundant. The two other isoforms, one 2 kDa larger and one 7 kDa smaller than mPus1p, were differentially expressed. The cDNA species for the three isoforms were cloned into expression plasmids; the proteins were synthesized in vitro and tested for pseudouridine synthase activity. The two isoforms, one containing an insert of 18 amino acids in a region of the enzyme assumed to be critical for activity, and the other, which has a deletion of the protein coding potential of two exons, were both inactive on tRNA substrates that mPus1p modifies.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.