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Gene Review

P4HB  -  prolyl 4-hydroxylase, beta polypeptide

Gallus gallus

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Disease relevance of P4HB


High impact information on P4HB

  • These findings demonstrate that R-cognin differs from other cell adhesion molecules and suggest possible mechanisms for its action in cell adhesion and neuronal differentiation [2].
  • Retina cognin (R-cognin) is a developmentally regulated 50-kDa protein that was isolated from chicken embryo retina cell membranes [2].
  • A chicken embryo retina cDNA library was constructed in lambda gt11 vector and was screened with polyclonal R-cognin antiserum, yielding several immunoreactive clones [2].
  • Protein disulfide isomerase (PDI), a catalyst of oxidative protein folding, has a variety of effects on the yield of native lysozyme during the oxidative refolding of the reduced, denatured protein [3].
  • Chicken and normal human PDI proteins showed tissue- and developmental-specific enhancement of cell aggregation identical to R-cognin, and this activity was blocked by inactivation of the -WCGHC- motifs which function in disulfide exchange [4].

Chemical compound and disease context of P4HB


Biological context of P4HB


Anatomical context of P4HB

  • Thus, the observations are consistent with a role for R-cognin in the formation or maintenance of functional cell-cell connections within the entire retina prior to developmental day 11, or in retinal ganglion cell layer formation or stability subsequent to embryonic day 11 [1].
  • Our results indicate that the CPH beta/PDI gene is methylated at the Hha I site in the 4th exon in erythrocytes whereas the same sites in tendon and cornea are hypomethylated [8].
  • The basal cells of corneal epithelium express CPH beta/PDI, but the superficial cell layers of stratified corneas of 19-day-old chick embryos do not [8].

Associations of P4HB with chemical compounds

  • Dependence of retina cell aggregation on disulfide exchange activity was shown by blocking that activity with the inhibitor, DTNB, or with a recombinant human PDI with the -WCGHC- motif cysteines mutated [4].
  • We also show that treating R-cognin and chicken PDI with the thioreductase inhibitor 5,5'-dithio-bis (2-nitrobenzoic acid), which covalently binds to the functional cysteines of the thioreductase active sites, reduces the enhancement of cell aggregation [9].
  • When reduced, denatured lysozyme (1.6 mg/ml) is passed over a PDI column in 1-2 M urea in the presence of a glutathione redox buffer, the specific activity of the recovered lysozyme is identical to that of the native enzyme and the total recovery of the applied protein is 50-65% [10].
  • The action of R-cognin, a chick neural retina cell recognition glycoprotein, was investigated in vesicles of retina cell membranes [11].

Other interactions of P4HB


Analytical, diagnostic and therapeutic context of P4HB


  1. Distribution of R-cognin in late embryonic and post-hatching chicken retina. Dobi, E.T., Troccoli, N.M., Hausman, R.E. Invest. Ophthalmol. Vis. Sci. (1986) [Pubmed]
  2. cDNA for R-cognin: homology with a multifunctional protein. Krishna Rao, A.S., Hausman, R.E. Proc. Natl. Acad. Sci. U.S.A. (1993) [Pubmed]
  3. Protein disulfide isomerase exhibits chaperone and anti-chaperone activity in the oxidative refolding of lysozyme. Puig, A., Gilbert, H.F. J. Biol. Chem. (1994) [Pubmed]
  4. The cell adhesion molecule retina cognin is a cell surface protein disulfide isomerase that uses disulfide exchange activity to modulate cell adhesion. Pariser, H.P., Zhang, J., Hausman, R.E. Exp. Cell Res. (2000) [Pubmed]
  5. Distribution of R-cognin and choline acetyltransferase in the ganglion cell layer of developing chick neural retina. Dobi, E.T., Naya, F.J., Hausman, R.E. Cell Differ. (1988) [Pubmed]
  6. Molecular cloning of a multifunctional chicken protein acting as the prolyl 4-hydroxylase beta-subunit, protein disulphide-isomerase and a cellular thyroid-hormone-binding protein. Comparison of cDNA-deduced amino acid sequences with those in other species. Parkkonen, T., Kivirikko, K.I., Pihlajaniemi, T. Biochem. J. (1988) [Pubmed]
  7. Cognin distribution during differentiation of embryonic chick retinal cells in vitro. Hausman, R.E., Katz, M.S., Dobi, E.T., Offermann, J. Int. J. Dev. Neurosci. (1986) [Pubmed]
  8. Expression and methylation of the beta-subunit gene of prolyl 4-hydroxylase: in erythrocytes, tendon and cornea of chick embryos. Chida, Y., Ishizaki, M., Nakazawa, M., Kao, W.W. Connect. Tissue Res. (1992) [Pubmed]
  9. Thioreductase activity of retina cognin and its role in cell adhesion. Pariser, H.P., Rakeman, A.S., Hausman, R.E. Brain Res. Dev. Brain Res. (1998) [Pubmed]
  10. Catalysis of protein folding by agarose-immobilized protein disulfide isomerase. Morjana, N.A., Gilbert, H.F. Protein Expr. Purif. (1994) [Pubmed]
  11. Vesicle interactions as a model for the retinal cell-cell recognition mediated by R-cognin. Troccoli, N.M., Hausman, R.E. Cell Differ. (1985) [Pubmed]
  12. Developmental localization of retina cognin synthesis by in situ hybridization. Phillips, J.L., Holdengreber, V., Ben-Shaul, Y., Zhang, J., Tolan, D.R., Hausman, R.E. Brain Res. Dev. Brain Res. (1997) [Pubmed]
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