Human cytoplasmic actin proteins are encoded by a multigene family.
We characterized nine human actin genes that we isolated (Engel et al., Proc. Natl. Acad. Sci. U.S.A. 78:4674-4678, 1981) from a library of cloned human DNA. Measurements of the thermal stability of hybrids formed between each cloned actin gene and alpha-, beta-, and gamma-actin mRNA demonstrated that only one of the clones is most homologous to sarcomeric actin mRNA, whereas the remaining eight clones are most homologous to cytoplasmic actin mRNA. By the following criteria we show that these nine clones represent nine different actin gene loci rather than different alleles or different parts of a single gene: (i) the restriction enzyme maps of the coding regions are dissimilar; (ii) each clone contains sufficient coding region to encode all or most of an entire actin gene; and (iii) each clone contains sequences homologous to both the 5' and 3' ends of the coding region of a cloned chicken beta-actin cDNA. We conclude, therefore, that the human cytoplasmic actin proteins are encoded by a multigene family.
Howard Hughes Medical Institute, Department of Medicine, Stanford University School of Medicine, Veterans Administration Medical Center, Palo Alto, California, USA.
J
J
Engel
P
P
Gunning
L
L
Kedes
D000199:Actins / Q000145:classification / Q000235:genetics*; D000483:Alleles; D000818:Animals; D003001:Cloning, Molecular; D003593:Cytoplasm / Q000737:chemistry*; D004587:Electrophoresis, Agar Gel; D023061:Gene Order / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D005810:Multigene Family / Q000235:genetics*; D009132:Muscles; D016366:Open Reading Frames / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D015183:Restriction Mapping
D000199:Actins; D020033:Protein Isoforms; D012333:RNA, Messenger