Identification of exon sequences and an exon binding protein involved in alternative RNA splicing of calcitonin/CGRP.
Transcripts derived from the 6 exon CALC I gene are differentially processed in a tissue-specific fashion to include or exclude a calcitonin-specific exon 4. All cell types which transcribe a second calcitonin/CGRP gene, CALC II, exclude exon 4. Substitution of the first 30 nucleotides of CALC I exon 4 with analogous CALC II sequence was sufficient to prevent recognition of exon 4 in in vitro or in vivo RNA splicing systems. UV crosslinking detected a approximately 66 kDa RNA-binding protein in HeLa nuclear extract which interacted with CALC I proximal exon sequence, but not CALC II or mutant sequences. UV crosslinking of this protein was inhibited by addition of nuclear extract from a cell type which normally causes exclusion of exon 4. These results identify an important regulatory element within exon 4 and support a model in which calcitonin production requires protein interaction with this sequence to facilitate exon recognition.
Cote
G J
GJ
Department of Medicine, Baylor College of Medicine, Houston, TX 77030.
Stolow
D T
DT
Peleg
S
S
Berget
S M
SM
Gagel
R F
RF
D000595:Amino Acid Sequence; D001483:Base Sequence; D002116:Calcitonin / Q000235:genetics* / Q000378:metabolism; D015740:Calcitonin Gene-Related Peptide / Q000235:genetics* / Q000378:metabolism; D004247:DNA; D005091:Exons; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D016133:Polymerase Chain Reaction; D012326:RNA Splicing; D016601:RNA-Binding Proteins / Q000378:metabolism* / Q000528:radiation effects; D014466:Ultraviolet Rays
D016601:RNA-Binding Proteins; D002116:Calcitonin; D004247:DNA; D015740:Calcitonin Gene-Related Peptide