Isolation and sequence of the gene for actin in Saccharomyces cerevisiae.

Abstract

The yeast Saccharomyces cerevisiae is known to contain the highly conserved and ubiquitous protein actin. We have used cloned actin sequences from Dictyostelium discoideum to identify and clone the actin gene in yeast. Hybridization to genomic fragments of yeast DNA suggest that there is a single actin gene in yeast. We have determined the nucleotide sequence of that gene and its flanking regions. The sequence of the gene reveals an intervening sequence of 309 base pairs in the coding sequences at the 5' end of the gene. The existence and location of the intervening sequence was verified by using the dideoxy chain termination technique to determine the sequence at the 5' terminus of the actin mRNA. The similarity of the splice junction sequences in this gene to those found in higher eukaryotes suggests that yeast must possess a similar splicing enzyme. Actin, a ubiquitous protein in higher organisms, plays an essential role in cell motility and structure. Although the functions of actin are diverse, ranging from muscle contraction to chromosome movement, the structure of the 42,000-dalton protein is highly conserved, both among the various types of actins found in higher organisms and in evolution (1, 2). The conservation of size and properties of actin has made it possible to identify actin in a number of lower eukaryotes. For example, the actin of Dictyostelhum discoideum has been studied extensively (3, 4); the amino acid sequence of Physarum polycephalum actin is known (5

Mutations Altering the Mitochondrial-Cytoplasmic Distribution of Mod5p Implicate the Actin Cytoskeleton and mRNA 3′ Ends and/or Protein Synthesis in Mitochondrial Delivery

“…Two plasmids, pT3 and pT7, that complemented the temperature-sensitive growth phenotype of mdp2-1 were found by screening a singlecopy YCp50 library (43). The plasmids contained overlapping 6-and 4-kbp inserts which hybridized to chromosome VI and the clone containing the ACT1 gene which codes for actin (27,52). ACT1 was responsible for complementation of mdp2-1 as determined by transposon mutagenesis of the pT3 plasmid and restriction analysis of mutant clones.…”

Interaction in Vivo and in Vitro between the Yeast Fimbrin, SAC6P, and a Polymerization-defective Yeast Actin (V266G and L267G)

“…Actin, required for a number of intracellular processes ranging from muscle contraction to cytokinesis, has a primary structure that is largely conserved from yeast to human (1). Actin is present in cells as two interchangeable forms, monomeric G-actin and filamentous F-actin.…”

Yeast actin is relatively well behaved

“…Both the increase in yeast actin critical concentration and the formation of actin particles, however, were completely inhibited by physiological and lower levels of Mg2+, a divalent cation whose concentration is expected to remain constant throughout the cell cycle. Second both the sequence and polymerization properties of actin from Acanthumeobu castellunii to man are remarkably conserved (Korn, 1982;Vandekerckhove et al, 1984), and the sequence of yeast actin is no exception (Gallwitz and Sures, 1980;Ng and Abelson, 1980). We therefore felt that an alternative protocol for thc purification of native yeast actin was desirable, both to re-examine its in vitro properties and also as a source of actin to characterize the interaction of yeast microfilamentassociated proteins with their homologous actin.…”