High impact information on unc-78

• The Caenorhabditis elegans unc-78 gene encodes a homologue of actin-interacting protein 1 required for organized assembly of muscle actin filaments [1].
• Point mutations in unc-78 alleles change conserved residues within different WD repeats of the UNC-78 protein and cause less severe phenotypes than a deletion allele, suggesting that these mutations partially impair the function of UNC-78 [1].
• These results indicate that the actin-regulating activity of AIP1 in cooperation with ADF/cofilin is essential for its in vivo function to regulate actin filament organization in muscle cells [2].
• However, the mechanism by which AIP1 interacts with ADF/cofilin and actin is not clearly understood [3].
• In the nematode Caenorhabditis elegans, an AIP1 ortholog is encoded by the unc-78 gene that is required for organized assembly of muscle actin filaments [4].

Biological context of unc-78

• These results suggest that muscle contraction has only minor influence on the tropomyosin's protective role against ADF/cofilin and AIP1, and that the two functions of tropomyosin in actin stability and muscle contraction are independent of each other [5].

Anatomical context of unc-78

• UNC-60B is normally localized in the diffuse cytoplasm and to the myofibrils in wild type but mislocalized to the actin aggregates in unc-78 mutants [1].
• In unc-78 mutants, the striated organization of actin filaments is disrupted, and large actin aggregates are formed in the body wall muscle cells, resulting in defects in their motility [1].

Associations of unc-78 with chemical compounds

• These experiments suggest a role for AIRAP/AIP-1 in protecting cells from the toxic effects of arsenite [6].

Physical interactions of unc-78

• These data support a model in which this conserved surface of AIP1 plays a direct role in enhancing fragmentation/depolymerization of ADF/cofilin-bound actin filaments but not in barbed end capping [3].

Regulatory relationships of unc-78

• Actin-interacting protein 1 (AIP1) is a WD40 repeat protein that enhances actin filament disassembly in the presence of actin-depolymerizing factor (ADF)/cofilin [3].

Other interactions of unc-78

• However, the myosin mutation showed much weaker suppression of the phenotypes of ADF/cofilin or AIP1 mutants than tropomyosin depletion [5].
• Identification of functional residues on Caenorhabditis elegans actin-interacting protein 1 (UNC-78) for disassembly of actin depolymerizing factor/cofilin-bound actin filaments [3].

References