title: Specificity of interactions of galectin-3 with Chrp, a cysteine- and histidine-rich cytoplasmic protein.
abstract: Earlier work described the cloning of a gene from murine 3T3 cells encoding a cytoplasmic protein Chrp containing a cysteine- and histidine-rich motif characteristic of Zn-finger proteins. The interaction of Chrp with murine galectin-3 first became evident in a yeast two-hybrid screen, but it was also observed in co-precipitation experiments from 3T3 cell lysates. Here, the formation of equimolar complexes by murine Chrp and hamster galectin-3 is shown. Moreover, we found that Chrp binds to the carbohydrate-recognition domain (CRD) of hamster galectin-3 and not to the N-terminal domain carrying the proline- and glycine-rich repeats characteristic of galectin-3 and absent in other galectins. However, galectin-1 does not bind to Chrp, although its CRD is homologous to the galectin-3 CRD. Finally, we report that galectin-3, in a complex with Chrp, binds to laminin in surface plasmon resonance experiments with similar kinetics and affinity as it does in the free state. The formation of higher-order complexes containing these proteins and additional binding partners may be relevant to cytoplasmic functions involving galectin-3.
authors.affiliation: National Institute for Medical Research, Mill Hill, London NW7 1AA, UK.
authors.forename: Sulemana
authors.initials: S
authors.lastname: Bawumia
authors.forename: Eminia A M
authors.initials: EA
authors.lastname: Barboni
authors.forename: Rajesh P
authors.initials: RP
authors.lastname: Menon
authors.forename: R Colin
authors.initials: RC
authors.lastname: Hughes
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001665:Binding Sites; D050260:Carbohydrate Metabolism; D002241:Carbohydrates / Q000737:chemistry; D017364:Collagenases; D003593:Cytoplasm / Q000737:chemistry / Q000378:metabolism; D037483:Galectin 1 / Q000737:chemistry / Q000378:metabolism; D037502:Galectin 3 / Q000737:chemistry* / Q000378:metabolism; D007797:Laminin / Q000737:chemistry; D051379:Mice; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry; D020349:Surface Plasmon Resonance
chemical_list: D002241:Carbohydrates; C406869:Cyhr1 protein, mouse; D037483:Galectin 1; D037502:Galectin 3; D007797:Laminin; D011506:Proteins; D011994:Recombinant Proteins; D017364:Collagenases