Domain 2 of gelsolin binds directly to tropomyosin.
Gelsolin is an actin filament severing protein composed of six similar structured domains that differ with respect to actin, calcium and polyphospho-inositide binding. Previous work has established that gelsolin binds tropomyosin [Koepf, E.K. and Burtnick, L.D. (1992) FEBS Lett. 309, 56-58]. We have produced various specific gelsolin domains in Escherichia coli in order to establish which of the six domains binds tropomyosin. Gelsolin domains 1-3 (G1-3), G1-2 and G2 all bind tropomyosin in a pH and calcium insensitive manner whereas binding of G4-6 to tropomyosin was barely detectable under the conditions tested. We conclude that gelsolin binds tropomyosin via domain 2 (G2).
Maciver
S K
SK
Genes and Development Group, Department of Biomedical Sciences, University of Edinburgh, Hugh Robson Building, George Square, Edinburgh, UK. skm@srv4.med.ed.ac.uk
Ternent
D
D
McLaughlin
P J
PJ
D000818:Animals; D001667:Binding, Competitive / Q000187:drug effects; D002118:Calcium / Q000494:pharmacology; D011232:Chemical Precipitation; D002846:Chromatography, Affinity; D018260:Gelsolin / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008027:Light; D008274:Magnesium / Q000494:pharmacology; D018482:Muscle, Skeletal; D010446:Peptide Fragments / Q000737:chemistry / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D011485:Protein Binding / Q000187:drug effects; D017434:Protein Structure, Tertiary; D011817:Rabbits; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D012542:Scattering, Radiation; D014335:Tropomyosin / Q000737:chemistry / Q000378:metabolism*; D014422:Turkeys; D014461:Ultracentrifugation
D018260:Gelsolin; D010446:Peptide Fragments; D011994:Recombinant Proteins; D014335:Tropomyosin; D008274:Magnesium; D002118:Calcium