| First Author | Babu GJ | Year | 2001 |
| Journal | Nat Cell Biol | Volume | 3 |
| Issue | 11 | Pages | 1025-9 |
| PubMed ID | 11715025 | Mgi Jnum | J:97927 |
| Mgi Id | MGI:3576700 | Doi | 10.1038/ncb1101-1025 |
| Citation | Babu GJ, et al. (2001) Loss of SM-B myosin affects muscle shortening velocity and maximal force development. Nat Cell Biol 3(11):1025-9 |
| abstractText | We used an exon-specific gene-targeting strategy to generate a mouse model deficient only in the SM-B myosin isoform. Here we show that deletion of exon-5B (specific for SM-B) in the gene for the heavy chain of smooth muscle myosin results in a complete loss of SM-B myosin and switching of splicing to the SM-A isoform, without affecting SM1 and SM2 myosin content. Loss of SM-B myosin does not affect survival or cause any overt smooth muscle pathology. Physiological analysis reveals that absence of SM-B myosin results in a significant decrease in maximal force generation and velocity of shortening in smooth muscle tissues. This is the first in vivo study to demonstrate a functional role for the SM-B myosin isoform. We conclude that the extra seven-residue insert in the surface loop 1 of SM-B myosin is a critical determinant of crossbridge cycling and velocity of shortening. |
