Non-AUG translational initiation of a short CAPC transcript generating protein isoform

Biochem Biophys Res Commun. 2009 Mar 13;380(3):508-13. doi: 10.1016/j.bbrc.2009.01.089. Epub 2009 Jan 23.

Abstract

CAPC (also known as LRRC26) is a new gene with restricted expression in normal tissues, and with expression in many cancers and cancer cell lines. We have identified and characterized a short-transcript of CAPC (S-CAPC). The nucleotide sequence analysis of CAPC mRNA showed that the transcription for S-CAPC starts at position +610 on the L-CAPC transcript. Interestingly, no translation initiation codon 'AUG' is present in this transcript. To determine if a non-AUG start site is utilized, the S-CAPC sequence was cloned into an expression vector with C-terminal myc and histidine tags, and transfected into 293T cells. Western blot and MALDI-TOF MS analysis on purified S-CAPC gave two distinct peaks at approximately 7.5 kDa. N-terminal amino acid sequencing of the purified 7.5 kDa protein product indicated that translation starts at the codon for cysteine on the S

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, N.I.H., Intramural

MeSH terms

  • Cell Line, Tumor
  • Codon, Initiator / metabolism*
  • Humans
  • Neoplasm Proteins / biosynthesis*
  • Neoplasm Proteins / genetics
  • Neoplasms / genetics
  • Neoplasms / metabolism*
  • Peptide Chain Initiation, Translational*
  • Protein Isoforms / biosynthesis
  • Protein Isoforms / genetics
  • RNA, Messenger / metabolism
  • Sequence Analysis, Protein
  • Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
  • Transcription, Genetic

Substances

  • Codon, Initiator
  • LRRC26 protein, human
  • Neoplasm Proteins
  • Protein Isoforms
  • RNA, Messenger