Pax genes

Source: Wikipedia, the free encyclopedia.
Paired domain
SCOP2
1pdn / SCOPe / SUPFAM
CDDcd00131
Available protein structures:
Pfam  structures / ECOD  
PDBRCSB PDB; PDBe; PDBj
PDBsumstructure summary

In

octapeptide as well as a Pro-Ser-Thr-rich C terminus may also be present.[2] Pax proteins
are important in early animal development for the specification of specific tissues, as well as during epimorphic limb regeneration in animals capable of such.

The paired domain was initially described in 1987 as the "paired box" in the Drosophila protein paired (prd; P06601).[3][4]

Groups

Within the mammalian family, there are four well defined groups of Pax genes.

  • Pax group 1 (Pax 1 and 9),
  • Pax group 2 (Pax 2, 5 and 8),
  • Pax group 3 (Pax 3 and 7) and
  • Pax group 4 (Pax 4 and 6).

Two more families, Pox-neuro and Pax-α/β, exist in basal bilaterian species.

murine Pax6.[7] The two rounds of whole-genome duplications in vertebrate evolution is responsible for the creation of as many as 4 paralogs for each Pax protein.[8]

Members

  • PAX1 has been identified in mice with the development of vertebrate and embryo segmentation, and some evidence this is also true in humans. It transcribes a 440 amino acid protein from 4 exons and 1,323bps in humans. In the mouse Pax1 mutation has been linked to undulated mutant suffering from skeletal malformations.[9]
  • renal-coloboma syndrome as well as oligomeganephronia.[10]
  • PAX3 has been identified with ear, eye and facial development. It transcribes a 479 amino acid protein in humans. Mutations in it can cause Waardenburg syndrome. PAX3 is frequently expressed in melanomas[11] and contributes to tumor cell survival.[12]
  • PAX4 has been identified with pancreatic islet beta cells. It transcribes a 350 amino acid protein from 9 exons and 2,010 bps in humans. Knockout mice lacking Pax4 expression fail to develop insulin-producing cells.[13] Pax4 undergoes mutual reciprocal interaction with the transcription factor Arx to endow pancreatic endocrine cells with insulin and glucagon cells respectively[14]
  • PAX5 has been identified with neural and spermatogenesis development and b-cell differentiation. It transcribes a 391 amino acid protein from 10 exons and 3,644bps in humans.
  • PAX6 (eyeless) is the most researched and appears throughout the literature as a "master control" gene for the development of eyes and sensory organs, certain neural and epidermal tissues as well as other homologous structures, usually derived from ectodermal tissues.[15]
  • satellite cells but not for the specification.[16]
  • PAX8 has been associated with thyroid specific expression. It transcribes a protein of 451 amino acids from 11 exons and 2,526bps in humans. Pax8 loss-of-function mutant mice lack follicular cells of the thyroid gland.[17]
  • PAX9 has found to be associated with a number of organ and other skeletal developments, particularly teeth. It transcribes a protein of 341 amino acids from 4 exons and 1,644bps in humans.

See also

References

  1. PMID 11750700
    .
  2. .
  3. .
  4. .
  5. .
  6. .
  7. .
  8. .
  9. ^ Balling et al., 1988
  10. ^ Online Mendelian Inheritance in Man (OMIM): 167409
  11. PMID 20421967
    .
  12. .
  13. ^ Sosa-Pineda et al., 1997
  14. ^ Collombat et al, 2003
  15. ^ Walter and Gruss, 1991
  16. PMID 15282552
    .
  17. ^ Mansouri et al.,1998

[1]==Further reading==

External links

This article incorporates text from the public domain Pfam and InterPro: IPR001523
  1. ^ Mansouri A et al. 1996