TY - JOUR
T1 - Divergent regulation of the sarcomere and the cytoskeleton
AU - Schevzov, Galina
AU - Fath, Thomas
AU - Vrhovski, Bernadette
AU - Vlahovich, Nicole
AU - Rajan, Sudarsan
AU - Hook, Jeff
AU - Joya, Josephine E.
AU - Lemckert, Frances
AU - Puttur, Franz
AU - Lin, Jim J.-C.
AU - Hardeman, Edna C.
AU - Wieczorek, David F.
AU - O'Neill, Geraldine M.
AU - Gunning, Peter W.
PY - 2008/1/4
Y1 - 2008/1/4
N2 - The existence of a feedback mechanism regulating the precise amounts of muscle structural proteins, such as actin and the actin-associated protein tropomyosin (Tm), in the sarcomeres of striated muscles is well established. However, the regulation of nonmuscle or cytoskeletal actin and Tms in nonmuscle cell structures has not been elucidated. Unlike the thin filaments of striated muscles, the actin cytoskeleton in nonmuscle cells is intrinsically dynamic. Given the differing requirements for the structural integrity of the actin thin filaments of the sarcomere compared with the requirement for dynamicity of the actin cytoskeleton in nonmuscle cells, we postulated that different regulatory mechanisms govern the expression of sarcomeric versus cytoskeletal Tms, as key regulators of the properties of the actin cytoskeleton. Comprehensive analyses of tissues from transgenic and knock-out mouse lines that overexpress the cytoskeletal Tms, Tm3 and Tm5NM1, and a comparison with sarcomeric Tms provide evidence for this. Moreover, we show that overexpression of a cytoskeletal Tm drives the amount of filamentous actin.
AB - The existence of a feedback mechanism regulating the precise amounts of muscle structural proteins, such as actin and the actin-associated protein tropomyosin (Tm), in the sarcomeres of striated muscles is well established. However, the regulation of nonmuscle or cytoskeletal actin and Tms in nonmuscle cell structures has not been elucidated. Unlike the thin filaments of striated muscles, the actin cytoskeleton in nonmuscle cells is intrinsically dynamic. Given the differing requirements for the structural integrity of the actin thin filaments of the sarcomere compared with the requirement for dynamicity of the actin cytoskeleton in nonmuscle cells, we postulated that different regulatory mechanisms govern the expression of sarcomeric versus cytoskeletal Tms, as key regulators of the properties of the actin cytoskeleton. Comprehensive analyses of tissues from transgenic and knock-out mouse lines that overexpress the cytoskeletal Tms, Tm3 and Tm5NM1, and a comparison with sarcomeric Tms provide evidence for this. Moreover, we show that overexpression of a cytoskeletal Tm drives the amount of filamentous actin.
UR - http://www.scopus.com/inward/record.url?scp=38049170726&partnerID=8YFLogxK
U2 - 10.1074/jbc.M704392200
DO - 10.1074/jbc.M704392200
M3 - Article
C2 - 17951248
AN - SCOPUS:38049170726
SN - 0021-9258
VL - 283
SP - 275
EP - 283
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 1
ER -