Download MendeleyStructural insights into double-stranded RNA recognition and transport by SID-1.
Zhang, J., Zhan, C., Fan, J., Wu, D., Zhang, R., Wu, D., Chen, X., Lu, Y., Li, M., Lin, M., Gong, J., Jiang, D.(2024) Nat Struct Mol Biol 31: 1095-1104
- PubMed: 38664565
- DOI: https://doi.org/10.1038/s41594-024-01276-9
- Primary Citation of Related Structures:
8HIP, 8HKE, 8J6M, 8J6O - PubMed Abstract:
RNA uptake by cells is critical for RNA-mediated gene interference (RNAi) and RNA-based therapeutics. In Caenorhabditis elegans, RNAi is systemic as a result of SID-1-mediated double-stranded RNA (dsRNA) across cells. Despite the functional importance, the underlying mechanisms of dsRNA internalization by SID-1 remain elusive. Here we describe cryogenic electron microscopy structures of SID-1, SID-1-dsRNA complex and human SID-1 homologs SIDT1 and SIDT2, elucidating the structural basis of dsRNA recognition and import by SID-1. The homodimeric SID-1 homologs share conserved architecture, but only SID-1 possesses the molecular determinants within its extracellular domains for distinguishing dsRNA from single-stranded RNA and DNA. We show that the removal of the long intracellular loop between transmembrane helix 1 and 2 attenuates dsRNA uptake and systemic RNAi in vivo, suggesting a possible endocytic mechanism of SID-1-mediated dsRNA internalization. Our study provides mechanistic insights into dsRNA internalization by SID-1, which may facilitate the development of dsRNA applications based on SID-1.
Organizational Affiliation:
College of Life Science and Technology, Key Laboratory of Molecular Biophysics of MOE, Huazhong University of Science and Technology, Wuhan, Hubei, China.
