title: Highly divergent actin expressed in a Chlamydomonas mutant lacking the conventional actin gene.
abstract: The Chlamydomonas mutant ida5 is deficient in the conventional actin gene and its axoneme lacks a subset of inner dynein arms that contain actin as a subunit. However, this mutant retains some other inner dynein arms because a novel protein (NAP) is expressed as a substitute for actin. In this study, we show by sequence analysis that NAP is identical to a putative actin-related protein, the cDNA sequence of which has recently been reported and shown to have 64% amino acid identity with conventional actin. A polyclonal antibody raised against a synthetic polypeptide corresponding to the NH2-terminal sequence of this protein specifically reacted with the spot corresponding to NAP in two-dimensional electrophoresis patterns. NAP apparently can substitute for conventional actin in some, but not all, cellular functions, and therefore can be regarded as a highly divergent actin. This unconventional actin appears to be expressed only when conventional actin is absent.
authors.affiliation: National Institute for Basic Biology, Okazaki, 444-8585, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kato-Minoura
authors.forename: S
authors.initials: S
authors.lastname: Uryu
authors.forename: M
authors.initials: M
authors.lastname: Hirono
authors.forename: R
authors.initials: R
authors.lastname: Kamiya
mesh_terms: D000199:Actins / Q000096:biosynthesis* / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D016825:Chlamydomonas reinhardtii / Q000235:genetics* / Q000276:immunology; D017353:Gene Deletion; D017343:Genes, Plant; D017125:Genes, Protozoan; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D015800:Protozoan Proteins / Q000096:biosynthesis / Q000235:genetics
chemical_list: D000199:Actins; D015800:Protozoan Proteins