Cloning of cDNAs encoding human interphotoreceptor retinoid-binding protein (IRBP) and comparison with bovine IRBP sequences

Gene. 1989 Aug 1;80(1):99-108. doi: 10.1016/0378-1119(89)90254-0.


We have determined the sequence of the human interphotoreceptor retinoid-binding protein mRNA from three separately isolated cDNAs. The sequence is 4.28 kb long and encodes a protein of 1247 amino acids (aa) including a putative signal peptide and propeptide. The sequence is shorter (by about 1.67 kb) than the bovine mRNA with the major difference in the lengths located in the 3'-untranslated region. We suggest that this resulted from an insertion in the bovine gene or a large deletion from the human gene. The insertion/deletion is flanked on either side by sequences that are similar in the bovine and human sequences. Like the bovine polypeptide, the deduced protein sequence from the human cDNA contains a fourfold repeat, with each repeat containing about 300 aa. Among the four repeats, the identity is about 30-40%. The identity between the complete bovine and human polypeptide sequences is 84%. The identity between the nucleotide sequences is 83% (excluding the major insertion/deletion). Comparison with the bovine gene indicates that the human sequence may lack about 5-10 bp at the 5' end of the cDNA; it, however, includes a poly(A) tail at the 3' end. Thus, the human sequence is virtually full length, is similar to the bovine sequence, and contains a striking fourfold repeat.

Publication types

  • Comparative Study

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cattle
  • Cloning, Molecular*
  • Codon
  • DNA / genetics
  • Eye Proteins / genetics*
  • Eye Proteins / metabolism
  • Glycosylation
  • Humans
  • Introns
  • Molecular Sequence Data
  • Protein Sorting Signals / genetics
  • RNA, Messenger / genetics
  • Repetitive Sequences, Nucleic Acid
  • Retinol-Binding Proteins / genetics*
  • Retinol-Binding Proteins / metabolism
  • Sequence Homology, Nucleic Acid


  • Codon
  • Eye Proteins
  • Protein Sorting Signals
  • RNA, Messenger
  • Retinol-Binding Proteins
  • interstitial retinol-binding protein
  • DNA

Associated data

  • GENBANK/M22453