Isolation and characterization of a novel actin filament-binding protein from Saccharomyces cerevisiae

Abstract

We puri®ed a novel actin ®lament (F-actin)-binding protein from the soluble fraction of Saccharomyces cerevisiae by successive column chromatographies by use of the 125 I-labeled F-actin blot overlay method. The puri®ed protein showed a minimum M r of about 140 kDa on SDS-polyacrylamide gel electrophoresis and we named it ABP140. A search with the partial amino acid sequences of ABP140 against the Saccharomyces Genome Database revealed that the open reading frame of the ABP140 gene (ABP140) corresponded to YOR239W fused with YOR240W by the +1 translational frame shift. The encoded protein consisted of 628 amino acids with a calculated M r of 71,484. The recombinant protein interacted with F-actin and showed the activity to crosslink F-actin into a bundle. Indirect immuno¯uorescence study demonstrated that ABP140 was colocalized with both cortical actin patches and cytoplasmic actin cables in intact cells. However, elimination of ABP140 by gene disruption did not show a deleterious e ect on cell growth or a ect the organization of F-actin. These results indicate that ABP140 is not required for cell growth but may be involved in the reorganization of F-actin in the budding yeast.

Mdm20 protein functions with Nat3 protein to acetylate Tpm1 protein and regulate tropomyosin–actin interactions in budding yeast

“…Acetylated Tpm1p then binds to individual actin filaments, stabilizing them and allowing them to become very long. Finally, Sac6p (fimbrin), perhaps aided by Abp140, bundles the filaments together into a cable (37,38).…”

Actin cytoskeleton in cell polarity and asymmetric division during mouse oocyte maturation

“…It is unclear why these probes labeled different actin structures within the mouse oocytes, but one possible explanation is that each of these probes could have a preference to somewhat different actin populations, as suggested by several studies [Asakura et al, 1998;Washington and Knecht, 2008;Munsie et al, 2009]. As multiple actin nucleators including formin-2, Spire 1/2 and Arp2/3 are present in meiotic I oocytes, each of which could nucleate a different population of actin filaments in mouse oocytes [Leader et al, 2002;Pfender et al, 2011;Sun et al, 2011].…”

Actin Bodies in Yeast Quiescent Cells: An Immediately Available Actin Reserve?

“…Among them, six showed a partial colocalization with actin bodies (Arc15p, Arc18p, Arc35p, Arp2p, Crn1p, and Srv2p), and five others (Abp1p, Abp140p, Cap1p, Cap2p, and Sac6p) strictly colocalized with actin bodies. Abp1p and Cap1p/ Cap2p are ABPs detected only in actin patches (Drubin et al, 1988;Amatruda and Cooper, 1992;Doyle and Botstein, 1996;Waddle et al, 1996), Abp140p is a protein preferentially found in actin cables (Asakura et al, 1998;Yang and Pon, 2002), and Sac6p has been detected in both actin cables and patches (Drubin et al, 1988;Doyle and Botstein, 1996). To confirm those results and increase when necessary the GFP signal in quiescent cells, 3xGFP fusion proteins were constructed and shown to be functional (see Materials and Methods).…”