title: Glycosylation modulates melanoma cell α2β1 and α3β1 integrin interactions with type IV collagen.
abstract: Although type IV collagen is heavily glycosylated, the influence of this post-translational modification on integrin binding has not been investigated. In the present study, galactosylated and nongalactosylated triple-helical peptides have been constructed containing the α1(IV)382-393 and α1(IV)531-543 sequences, which are binding sites for the α2β1 and α3β1 integrins, respectively. All peptides had triple-helical stabilities of 37 °C or greater. The galactosylation of Hyl(393) in α1(IV)382-393 and Hyl(540) and Hyl(543) in α1(IV)531-543 had a dose-dependent influence on melanoma cell adhesion that was much more pronounced in the case of α3β1 integrin binding. Molecular modeling indicated that galactosylation occurred on the periphery of α2β1 integrin interaction with α1(IV)382-393 but right in the middle of α3β1 integrin interaction with α1(IV)531-543. The possibility of extracellular deglycosylation of type IV collagen was investigated, but no β-galactosidase-like activity capable of collagen modification was found. Thus, glycosylation of collagen can modulate integrin binding, and levels of glycosylation could be altered by reduction in expression of glycosylation enzymes but most likely not by extracellular deglycosylation activity.
authors: From the Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida 34987 and.
authors: Maciej J
authors: MJ
authors: Stawikowski
authors: the Nova Southeastern University, Fort Lauderdale, Florida 33314.
authors: Beatrix
authors: B
authors: Aukszi
authors: From the Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida 34987 and.
authors: Roma
authors: R
authors: Stawikowska
authors: From the Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida 34987 and.
authors: Mare
authors: M
authors: Cudic
authors: From the Torrey Pines Institute for Molecular Studies, Port St. Lucie, Florida 34987 and gfields@tpims.org.
authors: Gregg B
authors: GB
authors: Fields
mesh_terms: D045744:Cell Line, Tumor; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D024141:Collagen Type IV / Q000378:metabolism*; D006031:Glycosylation; D006801:Humans; D038982:Integrin alpha2beta1 / Q000378:metabolism*; D039201:Integrin alpha3beta1 / Q000378:metabolism*; D008545:Melanoma / Q000378:metabolism*; D008958:Models, Molecular; D011485:Protein Binding; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D024141:Collagen Type IV; D038982:Integrin alpha2beta1; D039201:Integrin alpha3beta1
keywords: Collagen; Glycosylation; Hydroxylysine (Hyl); Integrins; Melanoma; Triple Helix