Interaction Of SM Protein And SNAREs Between The ER And The Golgi Complex In Arabidopsis

Plants are unmovable,so they are unable to escape from unfavorable conditions.In order to adapt to the environment,higher plant developed unique endomemrane system and vesicle transport mechanism for material and signaling communicaiton between cells and envorionment.In eukaryotic cells,protein transport and recycling are crucial for cell activities such as maintaining organelle functions,adaptation to the environment,cellular homeostasis,and intercellular communication."Cargo" transport between donor compartments and receptor organelles is carried out by transport vesicles.Vesicle trafficking can be divided into anterograde transport and retrograde transport,includeing vesicle budding,transport,tethering,docking and fusion steps.These processes are regulated by various factors such as SM protein,SNARE,tether,rab,and coat proteins.SM protein interacts with Qa-SNARE and play important roles in fusion step.SM protein plays important roles in the formation of SNARE complex and the fusion of transport vesicle and target membrane.SM proteins can be divided into four subfamilies,Sly1,Vps45,Vps33 and Secl subfimily.Most of the SM proteins have high affinity to the syntaxins.Every SM protein can only interact with one or two kinds of syntaxin.Due to the SM protein is highly conserved among species,if in the same transport pathway,different species SM protein they could partly rescue the growth defects of mutants.A typical SNARE complex contains Qa-,Qb-,and Qc-SNARE and R-SNARE..The overall structure of the Qa-SNARE consists of an N-terminal autoregulatory domain,a linker,the SNARE domain,and a C-terminal TM region.Plant Qa-SNARE plays important roles in various metabolism pathways,including cytokinesis,ionic transport,plant development,gravitropism,hormone signaling,interaction between plant and symbiosis bacteria,and plant defense.The SM protein between the ER and the Golgi apparatus is AtSly 1 in Arabidopis.And the Qa-SNAREs located to the ER and the Golgi apparatus are AtSYP81 and AtSYP31/AtSYP32,respectively.In this study,we observed the phenotypes of the mutants and transgenic plants:atsyp81,atsec20,atsly1,atsyp8×atsec20,atsyp81×atsly1,and AtSYP31AtSYP32 RNAi transgenic plants and checked their RNA expression level.We made pAtSYP31::GUS transgenic plants and analyzed tissue specific expression of AtSYP31.Interaction between AtSly 1 Myc-AtSYP31 and Myc-AtSYP32 and SNAREs were detected by pulldown and yeast two-hybrid analyses.In this study,we clarified the interaction between SM protein and Qa-SNAREs that function between the ER and the Golgi apparatus in Arabidopsis.