Isolation of CYP3A5P cDNA from human liver: a reflection of a novel cytochrome P-450 pseudogene

Biochim Biophys Acta. 1995 Mar 14;1261(1):161-5. doi: 10.1016/0167-4781(95)00016-a.


We have isolated, from a human liver cDNA library, a 1627 bp CYP3A5 cDNA variant (CYP3A5P) that contains several large insertions, deletions, and in-frame termination codons. By comparison with the genomic structure of other CYP3A genes, the major insertions in CYP3A5P cDNA demarcate the inferred sites of several CYP3A5 exons. The segments inserted in CYP3A5P have no homology with splice donor acceptor sites. It is unlikely that CYP3A5P cDNA represents an artifact of the cloning procedures since Southern blot analysis of human genomic DNA disclosed that CYP3A5P cDNA hybridized with a DNA fragment distinct from fragments that hybridized with either CYP3A5, CYP3A3 or CYP3A4. Moreover, analysis of adult human liver RNA on Northern blots hybridized with a CYP3A5P cDNA fragment revealed the presence of an mRNA with the predicted size of CYP3A5P. We conclude that CYP3A5P cDNA was derived from a separate gene, CYP3A5P, most likely a pseudogene evolved from CYP3A5.

Publication types

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

MeSH terms

  • Base Sequence
  • Biological Evolution
  • Cloning, Molecular
  • Cytochrome P-450 CYP2E1
  • Cytochrome P-450 CYP3A
  • Cytochrome P-450 Enzyme System / genetics*
  • DNA, Complementary / genetics*
  • Exons
  • Gene Library
  • Humans
  • Liver / chemistry*
  • Mixed Function Oxygenases / genetics*
  • Molecular Sequence Data
  • Multigene Family
  • Pseudogenes*
  • RNA, Messenger / biosynthesis
  • RNA, Messenger / genetics
  • Sequence Alignment
  • Sequence Deletion
  • Sequence Homology, Nucleic Acid
  • Terminator Regions, Genetic


  • DNA, Complementary
  • RNA, Messenger
  • Cytochrome P-450 Enzyme System
  • Mixed Function Oxygenases
  • Cytochrome P-450 CYP2E1
  • CYP3A protein, human
  • CYP3A5 protein, human
  • Cytochrome P-450 CYP3A
  • CYP3A4 protein, human

Associated data

  • GENBANK/M13785