Identification of exon sequences and an exon binding protein involved in alternative RNA splicing of calcitonin/CGRP

Nucleic Acids Res. 1992 May 11;20(9):2361-6. doi: 10.1093/nar/20.9.2361.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • Calcitonin / genetics*
  • Calcitonin / metabolism
  • Calcitonin Gene-Related Peptide / genetics*
  • Calcitonin Gene-Related Peptide / metabolism
  • DNA
  • Exons*
  • HeLa Cells
  • Humans
  • Molecular Sequence Data
  • Mutation
  • Polymerase Chain Reaction
  • RNA Splicing*
  • RNA-Binding Proteins / metabolism*
  • RNA-Binding Proteins / radiation effects
  • Ultraviolet Rays


  • RNA-Binding Proteins
  • Calcitonin
  • DNA
  • Calcitonin Gene-Related Peptide