Disease relevance of ABP1

• Hepatitis B virus core protein interacts with the C-terminal region of actin-binding protein [1].

High impact information on ABP1

• In unpolarized PMN leukocytes, ABP and myosin had a diffuse distribution with some predilection for the cortex [2].
• In PMN leukocytes fixed during phagocytosis of the yeast particles, antimyosin and anti-ABP staining concentrated strikingly in the distal portions of the pseudopod embracing the yeasts [2].
• In polarized PMN leukocytes crawling toward yeast particles, myosin and ABP staining concentrated in the anterior pseudopod [2].
• Distribution of actin-binding protein and myosin in polymorphonuclear leukocytes during locomotion and phagocytosis [2].
• ABP1p is localized to the cortical cytoskeleton and its overproduction causes assembly of the cortical actin cytoskeleton at inappropriate sites on the cell surface, resulting in delocalized surface growth [3].

Biological context of ABP1

• This approach is based on the assumption that an actin mutation that specifically impairs the interaction with an actin-binding protein will cause a phenotype similar to a null mutation in the gene that encodes the actin-binding protein [4].
• Abplp is a yeast cortical actin-binding protein that contains an SH3 domain similar to those found in signal transduction proteins that function at the membrane/cytoskeleton interface [5].
• We present evidence that SH3 domains mediate at least two independent functions of the Saccharomyces cerevisiae actin-binding protein Abp1p in vivo [6].
• This gene is required for growth at high temperature, viability in the absence of Abp1p, polarization of the cortical actin cytoskeleton, and endocytosis [7].
• Here, we report the crystal structure of the Saccharomyces cerevisiae Abp1 actin-binding actin depolymerizing factor homology (ADFH) domain and dissect its activities by mutagenesis [8].

Anatomical context of ABP1

• Thus, Abp1 acts as an adaptor protein in the localization or concentration of Sjl2 during late stages of endocytic vesicle formation [9].
• Abp1 regulates pseudopodium number in chemotaxing Dictyostelium cells [10].
• Hip1R, an F-actin-binding protein that associates with clathrin-coated vesicles, may physically link endocytic vesicles to actin filaments [11].
• Distribution of actin-binding protein and myosin in macrophages during spreading and phagocytosis [12].
• Interaptin, an actin-binding protein of the alpha-actinin superfamily in Dictyostelium discoideum, is developmentally and cAMP-regulated and associates with intracellular membrane compartments [13].

Associations of ABP1 with chemical compounds

• The NH2-terminal 16kD of Abp1p, a 65-kD yeast protein identified by its ability to bind to actin filaments, is 23% identical to yeast cofilin [14].
• Consistent with this, the SH3 domain-containing protein Abp1 physically associates with Sjl2 through its proline-rich domain [9].
• ABP1p is a novel protein with a 50 amino-acid C-terminal domain that is very similar to the SH3 domain in the non-catalytic region of nonreceptor tyrosine kinases (including those encoded by the proto-oncogenes c-src and c-abl), in phospholipase C gamma and in alpha-spectrin [3].
• Talin is an actin-binding protein involved in integrin-mediated cell adhesion and spreading [15].
• We also demonstrate that the SH3 domain of yeast Abp1p and that of the yeast RAS protein guanine nucleotide exchange factor Cdc25p complex with adenylyl cyclase in vitro [16].

Physical interactions of ABP1

• Abp1p contains a single SH3 domain that has recently been shown to bind in vitro to the adenylyl cyclase-associated protein Srv2p [6].
• We also show that a site in Abp1p itself is specifically bound by the SH3 domain of the actin-associated protein Rvs167p [6].

Regulatory relationships of ABP1

• YIH1 is an actin-binding protein that inhibits protein kinase GCN2 and impairs general amino acid control when overexpressed [17].
• In the years following its discovery, profilin's role in vivo progressed from that of a simple actin-binding protein which inhibits actin polymerization, to one which, as an important regulator of the cytoskeleton, can even promote actin polymerization under the appropriate circumstances [18].

Other interactions of ABP1

• Direct regulation of Arp2/3 complex activity and function by the actin binding protein coronin [19].
• First, since mutations in pairs of actin-binding protein genes cause inviability, the actin cytoskeleton of yeast does not contain a high degree of redundancy [20].
• Abp1 null mutations, like rvs167 mutations, result in defects in sporulation and reduced viability under certain suboptimal growth conditions [6].
• Double mutants lacking fimbrin and either Abp1p or capping protein show negative synthetic effects on growth, in the most extreme case resulting in lethality [20].
• The apparent redundancy between Sla1p and Abp1p resides in the C-terminal repeat region of Sla1p [21].

Analytical, diagnostic and therapeutic context of ABP1

• Structural and functional dissection of the Abp1 ADFH actin-binding domain reveals versatile in vivo adapter functions [8].
• We used indirect immunofluorescence to study the redistribution of myosin and ABP molecules in rabbit PMN leukocytes during locomotion and phagocytosis [2].
• We examined the distribution of ABP and myosin molecules in acetone-fixed rabbit lung macrophages by means of immunofluorescence [12].
• SspH2 interacted with the actin-binding protein profilin in the yeast two-hybrid assay and by affinity chromatography [22].
• The design of a hyperstable mutant of the Abp1p SH3 domain by sequence alignment analysis [23].

References