The mammalian pannexin family is homologous to the invertebrate innexin gap junction proteins

Genomics. 2004 Apr;83(4):706-16. doi: 10.1016/j.ygeno.2003.09.025.


We have cloned the genes PANX1, PANX2 and PANX3, encoding putative gap junction proteins homologous to invertebrate innexins, which constitute a new family of mammalian proteins called pannexins. Phylogenetic analysis revealed that pannexins are highly conserved in worms, mollusks, insects and mammals, pointing to their important function. Both innexins and pannexins are predicted to have four transmembrane regions, two extracellular loops, one intracellular loop and intracellular N and C termini. Both the human and mouse genomes contain three pannexin-encoding genes. Mammalian pannexins PANX1 and PANX3 are closely related, with PANX2 more distant. The human and mouse pannexin-1 mRNAs are ubiquitously, although disproportionately, expressed in normal tissues. Human PANX2 is a brain-specific gene; its mouse orthologue, Panx2, is also expressed in certain cell types in developing brain. In silico evaluation of Panx3 expression predicts gene expression in osteoblasts and synovial fibroblasts. The apparent conservation of pannexins between species merits further investigation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blotting, Northern
  • Brain / metabolism
  • Cloning, Molecular
  • Connexins / genetics*
  • Connexins / physiology*
  • DNA, Complementary / metabolism
  • Databases as Topic
  • Exons
  • Gap Junctions
  • Gene Library
  • Genome
  • Humans
  • In Situ Hybridization
  • Introns
  • Mice
  • Models, Genetic
  • Molecular Sequence Data
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism*
  • Phylogeny
  • Polymerase Chain Reaction
  • Protein Structure, Tertiary
  • RNA, Complementary / metabolism
  • RNA, Messenger / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Homology, Amino Acid
  • Synovial Membrane / metabolism
  • Tissue Distribution


  • Connexins
  • DNA, Complementary
  • Nerve Tissue Proteins
  • PANX1 protein, human
  • PANX2 protein, human
  • PANX3 protein, human
  • Panx2 protein, mouse
  • RNA, Complementary
  • RNA, Messenger

Associated data

  • GENBANK/AF207817
  • GENBANK/AF398506
  • GENBANK/AF398507
  • GENBANK/AF398508
  • GENBANK/AF398509
  • GENBANK/AF398510
  • GENBANK/AF406650
  • GENBANK/BK000624
  • GENBANK/BK000662