外囊复合体是一个多亚基进化保守的复合体,最初被证明主要与囊泡向质膜的转运有关。最近的一份报告(Kulich等人。,2013年交通;在新闻中)揭示了AtEXO70B1,拟南芥植物外囊复合体的多个亚基之一,与自噬相关的Atg8f蛋白共同转运至液泡。该途径不涉及高尔基体。AtEXO70B1和Atg8f的共定位表明这两种蛋白质都一起转运到液泡中,或者,或者,Atg8与位于AtEXO70B1多肽内的推定的Atg8相互作用基序(AIM)结合,显然为运输到液泡的自噬复合物形成了束缚复合物。在本增编中,通过使用生物信息学方法,我们显示AtEXO70B1以及拟南芥EXO70外囊亚基的另外20个旁系同源物各自具有一个或多个AIM,其共有序列暗示它们与Atg8的高保真结合。这表明自噬机制强烈参与组装,运输,显然还有AtEXO70B1的功能以及外囊亚复合物。
The exocyst complex is a multi-subunits evolutionary conserved complex, which was originally shown to be primarily associated with vesicular transport to the plasma membrane. A recent report (Kulich et al., 2013 Traffic; In Press) revealed that AtEXO70B1, one of the multiple subunits of the exocyst complex of Arabidopsis thaliana plants, is co-transported with the autophagy-associated Atg8f protein to the vacuole. This pathway does not involve the Golgi apparatus. The co-localization of AtEXO70B1 and Atg8f suggests either that both of these proteins are co-transported together to the vacuole or, alternatively, that Atg8 binds to a putative Atg8 interacting motif (AIM) located within the AtEXO70B1 polypeptide, apparently forming a tethering complex for an autophagic complex that is transported to the vacuole. In the present addendum, by tooling a bioinformatics approach, we show that AtEXO70B1 as well as the additional 20 paralogs of Arabidopsis EXO70 exocyst subunits each possess one or more AIMs whose
consensus sequence implies their high fidelity binding to Atg8. This indicates that the autophagy machinery is strongly involved in the assembly, transport, and apparently also the function of AtEXO70B1 as well as the exocyst sub complex.