The RGD (Arg-Gly-Asp) is a potential cell-binding motif of UNC-52/PERLECAN

UNC-52/perlecan is a basement membrane (BM) proteoglycan playing an essential role in the muscle cell attachment of C. elegans. The UNC-52 protein contains two RGD (Arg-Gly-Asp) motifs in domains III and IV, a well-characterized tripeptide known for binding to mammalian beta integrin. To investigate the role of the RGD motif in UNC-52/perlecan, we created two mutations in the (2021)RGD(2023) motif: one mutation changed the RGD to an RGE, and the other deleted the RGD motif. The RGE(2023) caused defective actin filaments and aberrant localization of PAT-3 beta integrin and TLN-1/talin. Additionally, the in-frame deletion of RGD(2023) resulted in a paralyzed and arrested at two-fold embryonic stages (Pat) phenotype, which is the identical phenotype of the pat-3 beta integrin null allele. These results indicate that RGD(2023) is a potential ligand for cell binding and is essential for development and survival. Furthermore, our analysis reveals that the RGD of an invertebrate BM molecule is a potential cell-binding motif, suggesting that the function of the RGD motif is conserved among species. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

UNC-52/perlecan is a basement membrane proteoglycan essential for muscle cell attachment in C. elegans. Mutations in the RGD motif of UNC-52/perlecan affect actin filaments and integrin localization, leading to developmental defects and paralysis. The RGD motif is a potential conserved cell-binding motif in invertebrates.