The rice DUF1620-containing and WD40-like repeat protein is required for the assembly of the restoration of fertility complex

• Published in: The New phytologist Vol. 210; no. 3; pp. 934 - 945
• Main Authors: Qin, Xiaojian, Huang, Qi, Xiao, Haijun, Zhang, Qiannan, Ni, Chenzi, Xu, Yanghong, Liu, Gai, Yang, Daichang, Zhu, Yingguo, Hu, Jun
• Format: Journal Article
• Language: English
• Published: England New Phytologist Trust 01.05.2016; Wiley Subscription Services, Inc
• Subjects: Amino Acid Sequence; assembly; Conserved Sequence; cytoplasmic male sterility (CMS); Fertility; Gene Expression Regulation, Plant; Gene Silencing; Hong‐Lian (HL) type; Membrane Proteins - chemistry; Membrane Proteins - metabolism; Mitochondrial Membranes - metabolism; Oryza - genetics; Oryza - physiology; Plant Infertility - genetics; Plant Proteins - chemistry; Plant Proteins - metabolism; Plants, Genetically Modified; Protein Binding; Protein Subunits - chemistry; Protein Subunits - metabolism; Repetitive Sequences, Amino Acid; restoration of fertility complex (RFC); RNA, Messenger - genetics; RNA, Messenger - metabolism; Sequence Alignment; WD40‐like repeat; assembly; WD40-like repeat; restoration of fertility complex (RFC); Hong-Lian (HL) type; cytoplasmic male sterility (CMS)
• ISSN: 0028-646X; 1469-8137
• DOI: 10.1111/nph.13824

Cytoplasmic male sterility (CMS) and restoration of fertility (Rf) are widely distributed in plant species utilized by humans. RF5 and GRP162 are subunits of the restoration of fertility complex (RFC) in Hong-Lian rice. Despite the fact that the RFC is 400–500 kDa in size, the other proteins or factors in the complex still remain unknown. Here, we identified RFC subunit 3, which encodes a DUF1620-containing and WD40-like repeat protein (RFC3) that is present in all tissues but highly expressed in leaves. We established that RFC3 interacts with both RF5 and GRP162 in vitro and in vivo, and is transported into the mitochondria as a membrane protein. Furthermore, CMS RNA (atp6-orfH79) and CMS cytotoxic protein (ORFH79) accumulate when RFC3 is silenced in restorer lines. We presented the analysis with blue-native polyacrylamide gel electrophoresis, indicating that RFC is disrupted in the RNAi line. We concluded that RCF3 is indispensable as a scaffold protein for the assembly of the RFC complex. We unveil a new molecular player of the RFC in the Rf pathway in rice and propose the model of RFC based on these data.