Ponsin interacts with Nck adapter proteins: implications for a role in cytoskeletal remodelling during differentiation of skeletal muscle cells.
Skeletal muscle differentiation is a complex process: It is characterised by changes in gene expression and protein composition. Simultaneously, a dramatic remodelling of the cytoskeleton and associated cell-matrix contacts, the costameres, occurs. The expression and localisation of the protein ponsin at cell-matrix contacts marks the establishment of costameres. In this report we show that skeletal muscle cells are characterised by a novel ponsin isoform, which contains a large insertion in its carboxy-terminus. This skeletal muscle-specific module binds the adapter proteins Nck1 and Nck2, and increased co-localisation of ponsin with Nck2 is observed at remodelling cell-matrix contacts of differentiating skeletal muscle cells. Since this ponsin insertion can be phosphorylated, it may adjust the interaction affinity with Nck adapter proteins. The novel ponsin isoform and its interaction with Nck1/2 provide exciting insight into the convergence of signalling pathways at the costameres, and its crucial role for skeletal muscle differentiation and re-generation.
Gehmlich
Katja
K
Institute of Biochemistry and Biology, Cell Biology, University of Potsdam, Germany. k.gehmlich@ucl.ac.uk
Hayess
Katrin
K
Legler
Christof
C
Haebel
Sophie
S
Van der Ven
Peter F M
PF
Ehler
Elisabeth
E
Fürst
Dieter O
DO
D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism*; D006801:Humans; D051379:Mice; D018101:Mice, Inbred mdx; D008840:Microfilament Proteins / Q000737:chemistry / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008954:Models, Biological; D008969:Molecular Sequence Data; D032342:Muscle Cells / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000166:cytology*; D009137:Muscular Dystrophy, Animal / Q000473:pathology; D016254:Mutagenesis, Insertional; D015513:Oncogene Proteins / Q000378:metabolism*; D009928:Organ Specificity; D010766:Phosphorylation; D010768:Phosphoserine; D010769:Phosphothreonine; D011392:Proline / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D020539:Sequence Analysis, Protein; D013379:Substrate Specificity; D015854:Up-Regulation / Q000235:genetics
D048868:Adaptor Proteins, Signal Transducing; D008840:Microfilament Proteins; C078332:Nck protein; D015513:Oncogene Proteins; C119201:ponsin; D010769:Phosphothreonine; D010768:Phosphoserine; D011392:Proline; D020928:Mitogen-Activated Protein Kinases