Tropomyosin isoforms: divining rods for actin cytoskeleton function.
Actin filament functional diversity is paralleled by variation in the composition of isoforms of tropomyosin in these filaments. Although the role of tropomyosin is well understood in skeletal muscle, where it regulates the actin-myosin interaction, its role in the cytoskeleton has been obscure. The intracellular sorting of tropomyosin isoforms indicated a role in spatial specialization of actin filament function. Genetic manipulation and protein chemistry studies have confirmed that these isoforms are functionally distinct. Tropomyosins differ in their recruitment of myosin motors and their interaction with actin filament regulators such as ADF-cofilin. Tropomyosin isoforms have therefore provided a powerful mechanism to diversify actin filament function in different intracellular compartments.
Gunning
Peter W
PW
Oncology Research Unit, The Children's Hospital at Westmead, Locked Bag 4001, Westmead NSW 2145, Australia. peterg3@chw.edu.au
Schevzov
Galina
G
Kee
Anthony J
AJ
Hardeman
Edna C
EC
D000199:Actins / Q000378:metabolism*; D017398:Alternative Splicing / Q000235:genetics; D000818:Animals; D003599:Cytoskeleton / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D014335:Tropomyosin / Q000235:genetics / Q000378:metabolism*
D000199:Actins; D020033:Protein Isoforms; D014335:Tropomyosin