Galectin-3: A novel substrate for c-Abl kinase.
Galectin-3, a beta-galactoside-binding lectin, is found in cellular and extracellular location of the cell and has pleiotropic biological functions such as cell growth, cell adhesion and cell-cell interaction. It may exhibit anti- or pro-apoptotic activity depending on its localization and post-translational modifications. Two important post-translational modifications of galectin-3 have been reported: its cleavage and phosphorylation. Cleavage of galectin-3 was reported to be involved with angiogenic potential and apoptotic resistance. Phosphorylation of galectin-3 regulates its sugar-binding ability. In this report we have identified novel tyrosine phosphorylation sites in galectin-3 as well as the kinase responsible for its phosphorylation. Our results demonstrate that tyrosines at positions 79, 107 and 118 can be phosphorylated in vitro and in vivo by c-Abl kinase. Tyrosine 107 is the main target of c-Abl. Expression of galectin-3 Y107F mutant in galectin-3 null SK-Br-3 cells leads to morphological changes and increased motility compared to wild type galectin-3. Further investigation is needed to better understand the functional significance of the novel tyrosine phosphorylated sites of galectin-3.
Balan
Vitaly
V
Karmanos Cancer Institute, Wayne State University, Detroit, MI, USA. vitaly.balan@gmail.com
Nangia-Makker
Pratima
P
Jung
Young Suk
YS
Wang
Yi
Y
Raz
Avraham
A
D001665:Binding Sites / Q000235:genetics; D015153:Blotting, Western; D045744:Cell Line, Tumor; D002465:Cell Movement; D037502:Galectin 3 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D047468:Immunoprecipitation; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D009154:Mutation; D010766:Phosphorylation; D011485:Protein Binding; D011499:Protein Processing, Post-Translational; D016315:Proto-Oncogene Proteins c-abl / Q000235:genetics / Q000378:metabolism*; D013379:Substrate Specificity; D014443:Tyrosine / Q000235:genetics / Q000378:metabolism
D037502:Galectin 3; D008164:Luminescent Proteins; D014443:Tyrosine; D016315:Proto-Oncogene Proteins c-abl