Journal article
Effects of profilin and profilactin on actin structure and function in living cells
The Journal of cell biology, Vol.117(5), pp.1023-1029
06/01/1992
DOI: 10.1083/jcb.117.5.1023
PMCID: PMC2289477
PMID: 1577865
Abstract
Previous studies have yielded conflicting results concerning the physiological role of profilin, a 12-15-kD actin- and phosphoinositide-binding protein, as a regulator of actin polymerization. We have addressed this question by directly microinjecting mammalian profilins, prepared either from an E. coli expression system or from bovine brain, into living normal rat kidney (NRK) cells. The microinjection causes a dose-dependent decrease in F-actin content, as indicated by staining with fluorescent phalloidin, and a dramatic reduction of actin and alpha-actinin along stress fibers. In addition, it has a strong inhibitory effect toward the extension of lamellipodia. However, the injection of profilin causes no detectable perturbation to the cell-substrate focal contact and no apparent depolymerization of filaments in either the nonlamellipodial circumferential band or the contractile ring of dividing cells. Furthermore, cytokinesis of injected cells occurs normally as in control cells. In contrast to pure profilin, high-affinity profilin-actin complexes from brain induce an increase in total cellular F-actin content and an enhanced ruffling activity, suggesting that the complex may dissociate readily in the cell and that there may be multiple states of profilin that differ in their ability to bind or release actin molecules. Our results indicate that profilin and profilactin can function as effective regulators for at least a subset of actin filaments in living cells.
Details
- Title: Subtitle
- Effects of profilin and profilactin on actin structure and function in living cells
- Creators
- L G Cao - Cell Biology Group, Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545G G Babcock - Cell Biology Group, Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545P A Rubenstein - Cell Biology Group, Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545Yu-li Wang - Cell Biology Group, Worcester Foundation for Experimental Biology, Shrewsbury, Massachusetts 01545
- Resource Type
- Journal article
- Publication Details
- The Journal of cell biology, Vol.117(5), pp.1023-1029
- DOI
- 10.1083/jcb.117.5.1023
- PMID
- 1577865
- PMCID
- PMC2289477
- ISSN
- 0021-9525
- eISSN
- 1540-8140
- Language
- English
- Date published
- 06/01/1992
- Academic Unit
- Stead Family Department of Pediatrics; Biochemistry and Molecular Biology; Internal Medicine
- Record Identifier
- 9984025271102771
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