ISSN:
0886-1544
Keywords:
actinogelin
;
α-actinin
;
reconstituted actin-gel
;
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
,
Medicine
Notes:
We studied the properties of actinogelin, a Ca2+-regulated actin cross-linking protein isolated from Ehrlich tumor cells or rat liver. Chicken gizzard α-actinin was used as a Ca2+-insensitive control. Actinogelin, which has very high gelation activity under low Ca2+ conditions, was found using electron microscopic or fluorescence studies to induce formation of a characteristic structure in which actin filaments and bundles radiate to (or converge from) all directions from spot-like core structures. A similar structure was induced with actinogelin, even in the presence of 0 7 saturation of tropomyosin. No such structure was detected with actinogelin under high Ca2+ conditions, and only a few were found with gizzard α-actinin. Because reconstituted structures are similar to those observed intracellularly, actinogelin may be important in the formation of similar microfilament organization in the cells. It seems also important that these structures are reconstituted with only two purified protein components, i.e., actinogelin and actin.Immunocompetition studies showed that actinogelin and gizzard α-actinin partially shared antigenicity, and their molecular shape and peptide maps were similar. Their amino acid compositions [Kuo et al., 1982], subunit and domain structures, and binding sites on actin [Mimura and Asano, 1987] are also very similar. Therefore, it is concluded that actinogelin belongs to α-actinin superfamily proteins. Furthermore, the presence of functionally different subfamilies concerned with Ca2+ sensitivy, gelation-efficiency, and others is discussed. Actinogelin, which induces networks of actin filaments, may be classified as high gelation type.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cm.970100402
Permalink
