1. A novel 110 kDa form of myosin XVIIIA (MysPDZ) is tyrosine-phosphorylated after colony-stimulating factor-1 receptor signalling.
- Author
-
Cross M, Csar XF, Wilson NJ, Manes G, Addona TA, Marks DC, Whitty GA, Ashman K, and Hamilton JA
- Subjects
- Amino Acid Sequence, Animals, Cell Differentiation, Cell Line drug effects, Cell Line metabolism, Electrophoresis, Gel, Two-Dimensional, Gelsolin metabolism, Genes, fms, Heat-Shock Proteins metabolism, Isomerases metabolism, Macrophages drug effects, Mice, Molecular Sequence Data, Myeloid Cells metabolism, Myosins chemistry, Myosins isolation & purification, Nonmuscle Myosin Type IIA metabolism, Phosphorylation drug effects, Phosphotyrosine analysis, Protein Disulfide-Isomerases, Receptor, Macrophage Colony-Stimulating Factor drug effects, Recombinant Fusion Proteins physiology, Transfection, src-Family Kinases metabolism, Macrophage Colony-Stimulating Factor pharmacology, Myosins metabolism, Protein Processing, Post-Translational drug effects, Receptor, Macrophage Colony-Stimulating Factor physiology, Signal Transduction
- Abstract
Macrophage colony-stimulating factor (M-CSF or CSF-1) controls the development of macrophage lineage cells via activation of its tyrosine kinase receptor, c-Fms. After adding CSF-1 to M1 myeloid cells expressing CSF-1R (CSF-1 receptor), tyrosine phosphorylation of many cellular proteins occurs, which might be linked to subsequent macrophage differentiation. The biological significance and characterization of such proteins were explored by a dual strategy comprising two-dimensional SDS/PAGE analysis of cell lysates of CSF-1-treated M1 cells expressing the wild-type or a mutated receptor, together with an enrichment strategy involving a tyrosine-phosphorylated receptor construct. In the present study, we report the identification by MS of a novel, low-abundance, 110 kDa form of myosin XVIIIA (MysPDZ, myosin containing PDZ domain), which appears to be preferentially tyrosine-phosphorylated after CSF-1R activation when compared with other known isoforms. Receptor mutation studies indicate that CSF-1R-dependent tyrosine phosphorylation of p110myosin XVIIIA requires Tyr-559 in the cytoplasmic domain of the receptor and is therefore Src-family kinase-dependent. Gelsolin, Erp61 protein disulphide-isomerase and possibly non-muscle myosin IIA were also tyrosine-phosphorylated under similar conditions. Similar to the more abundant p190 isoform, p110 myosin XVIIIA lacks a PDZ domain and, in addition, it may lack motor activity. The phosphorylation of p110 myosin XVIIIA by CSF-1 may alter its cellular localization or target its association with other proteins.
- Published
- 2004
- Full Text
- View/download PDF