caa a22 4500 475745108 CHVBK 20180406123511.0 cr unu---uuuuu 170329e20000501xx s 000 0 eng 10.1023/A:1005640004495 doi (NATIONALLICENCE)springer-10.1023/A:1005640004495 Functional diversity between orthologous myosins with minimal sequence diversity [Elektronische Daten] [M. Canepari, R. Rossi, M. Pellegrino, R. Bottinelli, S. Schiaffino, C. Reggiani] To define the structural differences that are responsible for the functional diversity between orthologous sarcomeric myosins, we compared the rat and human β/slow myosins. Functional comparison showed that rat β/slow myosin has higher ATPase activity and moves actin filaments at higher speed in in vitro motility assay than human β/slow myosin. Sequence analysis shows that the loop regions at the junctions of the 25 and 50 kDa domains (loop 1) and the 50 and 20 kDa domains (loop 2), which have been implicated in determining functional diversity of myosin heavy chains, are essentially identical in the two orthologs. There are only 14 non-conservative substitutions in the two myosin heavy chains, three of which are located in the secondary actin-binding loop and flanking regions and others correspond to residues so far not assigned a functional role, including two residues in the proximal S2 domain. Interestingly, in some of these positions the rat β/slow myosin heavy chain has the same residues found in human cardiac α myosin, a fast-type myosin, and fast skeletal myosins. These observations indicate that functional and structural analysis of myosin orthologs with limited sequence diversity can provide useful clues to identify amino acid residues involved in modulating myosin function. Kluwer Academic Publishers, 2000 Canepari M. Institute of Human Physiology, University of Pavia, Pavia, Italy aut Rossi R. Institute of Human Physiology, University of Pavia, Pavia, Italy aut Pellegrino M. Institute of Human Physiology, University of Pavia, Pavia, Italy aut Bottinelli R. Institute of Human Physiology, University of Pavia, Pavia, Italy aut Schiaffino S. Department of Biomedical Sciences and CNR Centre of Muscle Biology and Physiopathology, University of Padova, Padova, Italy aut Reggiani C. Department of Anatomy and Physiology, University of Padova, Padova, Italy aut Journal of Muscle Research & Cell Motility Kluwer Academic Publishers 21/4(2000-05-01), 375-382 0142-4319 21:4<375 2000 21 10974 https://doi.org/10.1023/A:1005640004495 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1023/A:1005640004495 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Canepari M. Institute of Human Physiology, University of Pavia, Pavia, Italy aut NATIONALLICENCE 700 1- Rossi R. Institute of Human Physiology, University of Pavia, Pavia, Italy aut NATIONALLICENCE 700 1- Pellegrino M. Institute of Human Physiology, University of Pavia, Pavia, Italy aut NATIONALLICENCE 700 1- Bottinelli R. Institute of Human Physiology, University of Pavia, Pavia, Italy aut NATIONALLICENCE 700 1- Schiaffino S. Department of Biomedical Sciences and CNR Centre of Muscle Biology and Physiopathology, University of Padova, Padova, Italy aut NATIONALLICENCE 700 1- Reggiani C. Department of Anatomy and Physiology, University of Padova, Padova, Italy aut NATIONALLICENCE 773 0- Journal of Muscle Research & Cell Motility Kluwer Academic Publishers 21/4(2000-05-01), 375-382 0142-4319 21:4<375 2000 21 10974 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer