Calmodulin-like protein increases filopodia-dependent cell motility via up-regulation of myosin-10.
Human calmodulin-like protein (CLP) is an epithelial-specific protein that is expressed during cell differentiation but down-regulated in primary cancers and transformed cell lines. Using stably transfected and inducible HeLa cell lines, we found that CLP expression did not alter the proliferation rate and colony-forming potential of these cells. However, remarkable phenotypic changes were observed in CLP-expressing compared with control cells. Soft agar colonies of CLP-expressing cells had rough boundaries, with peripheral cells migrating away from the colony. Cells expressing CLP displayed a striking increase in the number and length of myosin-10-positive filopodia and showed increased mobility in a wound healing assay. This increase in wound healing capacity was prevented by small interference RNA-mediated down-regulation of myosin-10. Fluorescence microscopy and Western blotting revealed that CLP expression results in up-regulation of its target protein, myosin-10. This up-regulation occurs at the protein level by stabilization of myosin-10. Thus, CLP functions by increasing the stability of myosin-10, leading to enhanced myosin-10 function and a subsequent increase in filopodial dynamics and cell migration. In stratified epithelia, CLP may be required during terminal differentiation to increase myosin-10 function as cells migrate toward the upper layers and establish new adhesive contacts.
Bennett
Richard D
RD
Cell Biology and Genetics Program, Mayo Graduate School, Mayo Clinic College of Medicine, Minnesota 55905, USA.
Mauer
Amy S
AS
Strehler
Emanuel E
EE
D000595:Amino Acid Sequence; D001483:Base Sequence; D002147:Calmodulin / Q000235:genetics / Q000502:physiology*; D002455:Cell Division; D002465:Cell Movement / Q000502:physiology*; D017931:DNA Primers; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009218:Myosins / Q000235:genetics / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry; D011554:Pseudopodia / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D014162:Transfection
C082965:CALML3 protein, human; D002147:Calmodulin; D017931:DNA Primers; C498718:MYO10 protein, human; D010446:Peptide Fragments; D009218:Myosins