On the Origin of SERKs： Bioinformatics Analysis ol the Somatic Embryogenesis Receptor Kinases  

作　　者：Marije aan den Toorn Catherine Albrecht Sacco de Vdes 

机构地区：[1]Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, the Netherlands

出　　处：《Molecular Plant》2015年第5期762-782,共21页分子植物（英文版）

摘　　要：Somatic embryogenesis receptor-like kinases （SERKs） are leucine-rich repeat receptor-like kinases involved in several, seemingly unrelated, plant-signaling pathways. In Arabidopsis thaliana, functional and genetic analysis of four SERK proteins has indicated that they are only partly redundant; their functions overlap but each performs a specific subset of signaling roles. The molecular basis for the functional spec- ificity within this highly homologous protein family is currently not known. Sequence analysis of SERK pro- teins from different plant species indicates that the SERKs are a highly conserved protein family present in monocots, dicots, and non-vascular plants. Residues in the extracellular domain that are important for interaction with other receptor kinases are highly conserved, even among SERK members without a func- tion in the corresponding pathways. SERK2, for instance, does not function in the brassinosteroid pathway, does not interact with BRI1, but is conserved in its BRIl-interacting domain. Further sequence analysis indicates that SERK3/BAK1 and SERK4/BKK1 have diverged from the original SERK protein in both their extracellular and cytoplasmic domains. Functional analysis of chimeric SERK proteins shows that different domains provide the SERK proteins with different functional specificity. For instance, the SERK1 or SERK2 extracellular domains are essential for SERK function in male sporogenesis, while the SERK3 extracellular and cytoplasmic domains are essential for SERK3 activity in brassinosteroid and flagellin signaling. The emerging picture is that SERKs are ancient genes, whose products have been recruited as co-receptors in the newly evolved signaling pathways. The SERK ligand-binding and protein-protein interaction domains are highly conserved, allowing all SERKs to form complexes, albeit with different affinity. However, specific functional residues must have been altered, in both the extracellular and intracellular domains, to allow for the observed differences in functionalitySomatic embryogenesis receptor-like kinases （SERKs） are leucine-rich repeat receptor-like kinases involved in several, seemingly unrelated, plant-signaling pathways. In Arabidopsis thaliana, functional and genetic analysis of four SERK proteins has indicated that they are only partly redundant; their functions overlap but each performs a specific subset of signaling roles. The molecular basis for the functional spec- ificity within this highly homologous protein family is currently not known. Sequence analysis of SERK pro- teins from different plant species indicates that the SERKs are a highly conserved protein family present in monocots, dicots, and non-vascular plants. Residues in the extracellular domain that are important for interaction with other receptor kinases are highly conserved, even among SERK members without a func- tion in the corresponding pathways. SERK2, for instance, does not function in the brassinosteroid pathway, does not interact with BRI1, but is conserved in its BRIl-interacting domain. Further sequence analysis indicates that SERK3/BAK1 and SERK4/BKK1 have diverged from the original SERK protein in both their extracellular and cytoplasmic domains. Functional analysis of chimeric SERK proteins shows that different domains provide the SERK proteins with different functional specificity. For instance, the SERK1 or SERK2 extracellular domains are essential for SERK function in male sporogenesis, while the SERK3 extracellular and cytoplasmic domains are essential for SERK3 activity in brassinosteroid and flagellin signaling. The emerging picture is that SERKs are ancient genes, whose products have been recruited as co-receptors in the newly evolved signaling pathways. The SERK ligand-binding and protein-protein interaction domains are highly conserved, allowing all SERKs to form complexes, albeit with different affinity. However, specific functional residues must have been altered, in both the extracellular and intracellular domains, to allow for the observed differences in functionality

关 键 词：cell signaling signal transduction ARABIDOPSIS 

分 类 号：Q811.4[生物学—生物工程] S852.6[农业科学—基础兽医学]