Specific disruption of smooth muscle caldesmon expression in mice.
Caldesmon (CaD) is an actin-binding protein that is capable of inhibiting the actomyosin ATPase activity in vitro. CaD has a single gene that is alternatively spliced to generate the smooth muscle-specific form, h-CaD, and a shorter isoform, l-CaD, that is present only in non-muscle cells. The difference between h- and l-CaD is a highly charged repeating sequence, corresponding to a 35 nm-long single helical region that separates the N-terminal domain from the C-terminal domain of h-CaD. To test whether such an elongated h-CaD is essential for smooth muscles to function properly, we have specifically abrogated its expression in the mouse by targeting h-CaD without affecting the expression of l-CaD. After genotyping, we have obtained homozygous knockout mice that indeed lack h-CaD, but nevertheless express varying amounts of l-CaD in a tissue-dependent fashion. The contractility of smooth muscles isolated from the knockout animals is currently under investigation.
Guo
Hongqiu
H
Boston Biomedical Research Institute, 64 Grove Street, Watertown, MA 02472, USA.
Wang
C-L Albert
CL
D017398:Alternative Splicing; D000818:Animals; D002148:Calmodulin-Binding Proteins / Q000096:biosynthesis* / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D032389:Myocytes, Smooth Muscle / Q000378:metabolism*; D020033:Protein Isoforms / Q000096:biosynthesis
D002148:Calmodulin-Binding Proteins; D020033:Protein Isoforms