title: A ubiquitin ligase of symbiosis receptor kinase involved in nodule organogenesis.
abstract: The symbiosis receptor kinase (SymRK) is required for morphological changes of legume root hairs triggered by rhizobial infection. How protein turnover of SymRK is regulated and how the nodulation factor signals are transduced downstream of SymRK are not known. In this report, a SymRK-interacting E3 ubiquitin ligase (SIE3) was shown to bind and ubiquitinate SymRK. The SIE3-SymRK interaction and the ubiquitination of SymRK were shown to occur in vitro and in planta. SIE3 represents a new class of plant-specific E3 ligases that contain a unique pattern of the conserved CTLH (for C-terminal to LisH), CRA (for CT11-RanBPM), and RING (for Really Interesting New Gene) domains. Expression of SIE3 was detected in all tested tissues of Lotus japonicus plants, and its transcript level in roots was enhanced by rhizobial infection. The SIE3 protein was localized to multiple subcellular locations including the nuclei and plasma membrane, where the SIE3-SymRK interaction took place. Overexpression of SIE3 promoted nodulation in transgenic hairy roots, whereas downregulation of SIE3 transcripts by RNA interference inhibited infection thread development and nodule organogenesis. These results suggest that SIE3 represents a new class of E3 ubiquitin ligase, acts as a regulator of SymRK, and is involved in rhizobial infection and nodulation in L. japonicus.
authors: State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan 430070, China.
authors: Songli
authors: S
authors: Yuan
authors: Hui
authors: H
authors: Zhu
authors: Honglan
authors: H
authors: Gou
authors: Weiwei
authors: W
authors: Fu
authors: Lijing
authors: L
authors: Liu
authors: Tao
authors: T
authors: Chen
authors: Danxia
authors: D
authors: Ke
authors: Heng
authors: H
authors: Kang
authors: Qi
authors: Q
authors: Xie
authors: Zonglie
authors: Z
authors: Hong
authors: Zhongming
authors: Z
authors: Zhang
mesh_terms: D060054:Agrobacterium / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D005822:Genetic Vectors; D000070116:Lotus / Q000201:enzymology* / Q000235:genetics / Q000382:microbiology; D059128:Mesorhizobium / Q000254:growth & development*; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism; D055170:Plant Root Nodulation; D030821:Plants, Genetically Modified / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D010957:Plasmids; D025941:Protein Interaction Mapping; D011494:Protein Kinases / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D034622:RNA Interference; D015398:Signal Transduction; D013559:Symbiosis; D020798:Two-Hybrid System Techniques; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D054875:Ubiquitination
chemical_list: D010940:Plant Proteins; D044767:Ubiquitin-Protein Ligases; D011494:Protein Kinases