Actin-ADF/cofilin rod formation in Caenorhabditis elegans muscle requires a putative F-actin binding site of ADF/cofilin at the C-terminus.
Under a number of stress or pathological conditions, actin and actin depolymerizing factor (ADF)/cofilin form rod-like structures that contain abnormal bundles of actin filaments that are heavily decorated with ADF/cofilin. However, the mechanism of actin rod formation and the physiological role of actin rods are not clearly understood. Here, we report that overexpression of green fluorescent protein-fused UNC-60B, a muscle-specific ADF/cofilin isoform, in Caenorhabditis elegans body wall muscle induces formation of rod-like structures. The rods contained GFP-UNC-60B, actin-interacting protein 1 (AIP1), and actin, but not other major actin-associated proteins, thus resembling actin-ADF/cofilin rods found in other organisms. However, depletion or overexpression of AIP1 did not affect formation of the actin-GFP-UNC-60B rods, suggesting that AIP1 does not play a significant role in the rod assembly. Truncation of the C-terminal tail, a putative F-actin binding site, of UNC-60B abolished induction of the rod formation, strongly suggesting that stable association of UNC-60B with F-actin, which is mediated by its C-terminus, is required for inducing actin-ADF/cofilin rods. This study suggests that C. elegans can be a new model to study functions of actin-ADF/cofilin rods.
Ono
Kanako
K
Department of Pathology, Emory University, Atlanta, Georgia 30322, USA.
Ono
Shoichiro
S
D000199:Actins / Q000378:metabolism*; D000818:Animals; D030801:Animals, Genetically Modified; D001665:Binding Sites; D017173:Caenorhabditis elegans / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000378:metabolism*; D008840:Microfilament Proteins / Q000378:metabolism*; D009132:Muscles / Q000166:cytology / Q000378:metabolism*; D053140:Organelle Shape / Q000502:physiology; D015388:Organelles / Q000378:metabolism* / Q000648:ultrastructure
D000199:Actins; D029742:Caenorhabditis elegans Proteins; D008840:Microfilament Proteins; C495209:UNC-60 protein, C elegans; C423987:unc-78 protein, C elegans