Function Analysis Of SM Protein AtSLY1 In Arabidopsis Protein Transport

Higher plant cells contain a complicated endomembrane system to complete protein transport through vesicle trafficking mechanism.Most cells contain various transport vesicles that target to different destinations.The underlying molecular mechanisms are highly conserved in evolution.Vesicle trafficking includes four steps:budding,transport,tethering,and fusion.Sec1/Munc-18(SM)proteins play an important role on regulating vesicle transport by interacting with soluble N-ethylmaleimide-sensitive factor attachment protein receptors(SNAREs)at each vesicle fusion sites.SM proteins interact with syntaxin,an important component in SNARE complex,to regulate the assembly of SNARE complex,and promote overall membrane fusion process together with SNARE complex.Our previous study discovered that vesicle transport was blocked in the mutant of atufel,the syntaxin protein in Arabidopsis ER,which proved its function in vescle transport.In this research,we found SM protein AtSLY1 could bind to AtUfel in plant cells through pull-down.AtSLY1 was not necessary for plant growth by observing atslyl mutant and AtSLY1 RNAi lines.In Y2H research,we discovered that AtSLY1 could bind to AtUfel directly and AtUfel interacted with AtSLY1 through its N terminal region while both the N terminal domain and Sec1 domain of AtSLYl could interact with AtUfel.