Actin-related proteins in Anabaena spp. and Escherichia coli.
Actin has been described in all eukaryotic cells as the major microfilament cytoskeletal protein. Although prokaryotic cells do not have a cytoskeleton, proteins related to the latter have been found in different prokaryotic species. We have found prokaryotic actin-related proteins in the enterobacterium Escherichia coli and in the cyanobacteria Anabaena cylindrica and Anabaena variabilis. They were identified by the following criteria: (1) by cross-reaction with a fluorescent conjugated anti-actin (rat-brain) mAb by Western blot analysis (in total cellular extracts); (2) specific binding of acetone powder and soluble cellular extracts to DNase I; and (3) specific binding of cells and total cellular extracts to phalloidin. In E coli, specific binding of phalloidin labelled with rhodamine to cells was detected by spectrofluorometry. In total cellular extracts, three bands of 60, 43 and 35 kDa were weakly recognized by the mAb by Western blot analysis; this recognition increased when phalloidin was added to the extracts. Furthermore, three polypeptides of kDa were isolated by binding to DNase I, showing pI values of 6.7, 6.65 and 6.6, less acidic than all reported actin pI values. In A. cylindrica and A. variabilis, specific binding of phalloidin labelled with rhodamine to cells was also detected by spectrofluorometry. In total and soluble cellular extracts, the mAb recognized two bands of 45 and 40 kDa by Western blot analysis, but only the first was purified by binding to DNase I, and it showed three isoforms of pI values 6.8, 6.5 and 6.4. These results suggest the presence, in prokaryotes, of proteins with similar biochemical characteristics to eukaryotic actin.
Guerrero-Barrera
Alma L
AL
Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF 07000, Mexico.
García-Cuéllar
Claudia M
CM
División de Investigación Básica, Instituto Nacional de Cancerología, San Fernando No. 22, Tlalpan DF 14000, Mexico.|Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF 07000, Mexico.
Villalba
José D
JD
Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF 07000, Mexico.
Segura-Nieto
Magdalena
M
Departamento de Ingeniería Genética, Centro de Investigación y de Estudios Avanzados del IPN, Km 9.6, Libramiento Norte, Carretera Irapuato-León, Irapuato, Gto, Mexico.
Gómez-Lojero
Carlos
C
Departamento de Bioquímica, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF 07000, Mexico.
Reyes
Magda E
ME
Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF 07000, Mexico.
Hernández
José M
JM
Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF 07000, Mexico.
Garcia
Rosa M
RM
Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF 07000, Mexico.
de la Garza
Mireya
M
Departamento de Biología Celular, Centro de Investigación y de Estudios Avanzados del IPN, Apartado Postal 14-740, México, DF 07000, Mexico.
D000199:Actins / Q000737:chemistry* / Q000276:immunology; D017033:Anabaena / Q000737:chemistry* / Q000276:immunology / Q000648:ultrastructure; D000818:Animals; D000907:Antibodies, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D001704:Biopolymers; D015153:Blotting, Western; D003429:Cross Reactions; D003850:Deoxyribonuclease I / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry* / Q000276:immunology / Q000648:ultrastructure; D019143:Evolution, Molecular; D010590:Phalloidine / Q000378:metabolism; D010940:Plant Proteins / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D011485:Protein Binding; D051381:Rats; D013045:Species Specificity
D000199:Actins; D000907:Antibodies, Bacterial; D001426:Bacterial Proteins; D001704:Biopolymers; D010940:Plant Proteins; D010590:Phalloidine; D003850:Deoxyribonuclease I