Dynamic actin structures stabilized by profilin.
We describe the production and analysis of clonal cell lines in which we have overexpressed human profilin, a small ubiquitous actin monomer binding protein, to assess the role of profilin on actin function in vivo. The concentration of filamentous actin is increased in cells with higher profilin levels, and actin filament half-life measured in these cells is directly proportional to the steady-state profilin concentration. The distribution of actin filaments is altered by profilin overexpression. While parallel actin bundles crossing the cells are virtually absent in cells overexpressing profilin, the submembranous actin network of these cells is denser than in control cells. These results suggest that in vivo profilin regulates the stability, and thereby distribution, of specific dynamic actin structures.
Finkel
T
T
Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Theriot
J A
JA
Dise
K R
KR
Tomaselli
G F
GF
Goldschmidt-Clermont
P J
PJ
D000199:Actins / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure*; D000818:Animals; D016466:CHO Cells / Q000166:cytology; D002451:Cell Compartmentation; D002999:Clone Cells / Q000166:cytology; D003285:Contractile Proteins; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D005455:Fluorescent Antibody Technique; D006801:Humans; D008840:Microfilament Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D051304:Profilins; D011994:Recombinant Proteins / Q000494:pharmacology; D014162:Transfection
D000199:Actins; D003285:Contractile Proteins; D008840:Microfilament Proteins; C495738:PFN1 protein, human; D051304:Profilins; D011994:Recombinant Proteins