Novel actin-related proteins in vertebrates: similarities of structure and expression pattern to Arp6 localized on Drosophila heterochromatin.
Actin-related proteins (Arps), which share a basal structure with actin isoforms but possess different functions, have been identified in a wide variety of organisms. The Arps are classified into subfamilies based on the relatedness of their sequences and functions. Recently, several Arp subfamilies have been shown to be localized in the nucleus and included in protein complexes involved in the organization of chromatin structure, for example, in chromatin remodeling and histone acetyltransferase complexes. A member of the Arp6 subfamily in Drosophila, dArp6, is localized on centric heterochromatin together with heterochromatin protein 1 (HP1). We have identified the first examples of the Arp6 subfamily in vertebrates, novel human and chicken Arps, hArp6 and gArp6, respectively. They are closely related to each other (98% similar) and show apparent similarity to dArp6 (70%). In addition, the hArp6 gene possesses evolutionarily conserved exon/intron structures compared with genes for members of the Arp6 subfamily in invertebrates. Like Drosophila dArp6, gArp6 is expressed abundantly in the early developmental stages, when heterochromatin condensation and nuclear maturation occur. The finding of a conserved Arp6 subfamily in vertebrates will contribute to the understanding of molecular mechanisms of heterochromatin organization.
Kato
M
M
Laboratory of Molecular Biology, Department of Molecular and Cell Biology, Division of Life Science, Graduate School of Agricultural Science, Tohoku University, Tsutsumidori-Amamiyamachi 1-1, Aoba-ku, 981-8555, Sendai, Japan.
Sasaki
M
M
Mizuno
S
S
Harata
M
M
D000199:Actins / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D030161:Avian Proteins; D002642:Chick Embryo; D002645:Chickens / Q000235:genetics*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics* / Q000378:metabolism; D017124:Conserved Sequence; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins; D019143:Evolution, Molecular; D005091:Exons; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006570:Heterochromatin / Q000378:metabolism; D006801:Humans; D007438:Introns; D008297:Male; D008969:Molecular Sequence Data; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D014714:Vertebrates / Q000235:genetics*
C431141:ACTR6 protein, human; D000199:Actins; C498980:Arp6 protein, Drosophila; C498981:Arp6 protein, Gallus gallus; D030161:Avian Proteins; D002868:Chromosomal Proteins, Non-Histone; D029721:Drosophila Proteins; D006570:Heterochromatin