N-Acetylgalactosaminyltransferase 14, a novel insulin-like growth factor binding protein-3 binding partner

Biochem Biophys Res Commun. 2007 Jun 1;357(2):360-5. doi: 10.1016/j.bbrc.2007.03.153. Epub 2007 Apr 9.

Abstract

Insulin-like growth factor binding protein-3 (IGFBP-3) is known to inhibit cell proliferation and induce apoptosis in IGF-dependent and IGF-independent manners, but the mechanism underlying IGF-independent effects is not yet clear. In a yeast two-hybrid assay, IGFBP-3 was used as the bait to screen a human fetal liver cDNA library for it interactors that may potentially mediate IGFBP-3-regulated functions. N-Acetylgalactosaminyltransferase 14 (GalNAc-T14), a member of the GalNAc-Tases family, was identified as a novel IGFBP-3 binding partner. This interaction involved the ricin-type beta-trefoil domain of GalNAc-T14. The interaction between IGFBP-3 and GalNAc-T14 was reconfirmed in vitro and in vivo, using GST pull-down, co-immunoprecipitation and mammalian two-hybrid assays. Our findings may provide new clues for further study on the mechanism behind the IGF-independent effects of IGFBP-3 promoting apoptosis. The role of GalNAc-T14 as an intracellular mediator of the effects of IGFBP-3 need to be verified in future studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Binding Sites
  • Cell Line
  • Enzyme Activation
  • Humans
  • Insulin-Like Growth Factor Binding Protein 3 / metabolism*
  • Kidney / metabolism*
  • N-Acetylgalactosaminyltransferases / metabolism*
  • Protein Binding
  • Protein Interaction Mapping

Substances

  • Insulin-Like Growth Factor Binding Protein 3
  • N-Acetylgalactosaminyltransferases