Proteins of the ADF/cofilin family: essential regulators of actin dynamics.
Ubiquitous among eukaryotes, the ADF/cofilins are essential proteins responsible for the high turnover rates of actin filaments in vivo. In vertebrates, ADF and cofilin are products of different genes. Both bind to F-actin cooperatively and induce a twist in the actin filament that results in the loss of the phalloidin-binding site. This conformational change may be responsible for the enhancement of the off rate of subunits at the minus end of ADF/cofilin-decorated filaments and for the weak filament-severing activity. Binding of ADF/cofilin is competitive with tropomyosin. Other regulatory mechanisms in animal cells include binding of phosphoinositides, phosphorylation by LIM kinases on a single serine, and changes in pH. Although vertebrate ADF/cofilins contain a nuclear localization sequence, they are usually concentrated in regions containing dynamic actin pools, such as the leading edge of migrating cells and neuronal growth cones. ADF/cofilins are essential for cytokinesis, phagocytosis, fluid phase endocytosis, and other cellular processes dependent upon actin dynamics.
Bamburg
J R
JR
Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins 80523, USA. jbamburg@amar.colostate.edu
D051339:Actin Depolymerizing Factors; D000199:Actins / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D051345:Destrin; D019143:Evolution, Molecular; D006801:Humans; D007424:Intracellular Fluid / Q000378:metabolism / Q000502:physiology; D007674:Kidney Diseases / Q000473:pathology; D008840:Microfilament Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D019636:Neurodegenerative Diseases; D018980:Williams Syndrome / Q000473:pathology
D051339:Actin Depolymerizing Factors; D000199:Actins; C495824:DSTN protein, human; D051345:Destrin; D008840:Microfilament Proteins