Steffens Alexandra, Jakoby Marc, Hülskamp Martin
Botanical Institute, Cologne Biocenter, University of Cologne, Cologne, Germany.
Front Plant Sci. 2017 Nov 20;8:1969. doi: 10.3389/fpls.2017.01969. eCollection 2017.
Beige and Chediak Higashi (BEACH) domain-containing proteins (BDCPs) are facilitators of membrane-dependent cellular processes in eukaryotes. Mutations in BDCPs cause malfunctions of endosomal compartments in various cell types. Recently, the molecular analysis of the BDCP homolog gene () has revealed a molecular function in P-bodies and the regulation of RNA stability. We therefore aimed to analyze, whether SPI has also a role in membrane-dependent processes. In this study, we show that SPI physically interacts with endosomal sorting complex required for transport associated ATPase Suppressor of K-transport growth defect1 (SKD1) and its positive regulator, LYST Interacting Protein 5 (LIP5) and report genetic interactions between and and . We further show that the endosomal transport route of soluble proteins to the lytic vacuole is disturbed in double mutants but not in the single mutants. These vacuolar transport defects were suppressed by additional expression of SKD1. Our results indicate that the BEACH domain protein SPI has in addition to a role in P-bodies a function in endosomal transport routes.
含米色和切迪阿克-东垣（BEACH）结构域的蛋白（BDCPs）是真核生物中膜依赖性细胞过程的促进因子。BDCPs的突变会导致多种细胞类型内体区室功能异常。最近，对BDCP同源基因（）的分子分析揭示了其在P小体中的分子功能以及对RNA稳定性的调控。因此，我们旨在分析SPI是否也在膜依赖性过程中发挥作用。在本研究中，我们表明SPI与运输相关ATP酶K运输生长缺陷抑制因子1（SKD1）及其正向调节因子LYST相互作用蛋白5（LIP5）在内体分选复合体上发生物理相互作用，并报道了与和之间的遗传相互作用。我们进一步表明，可溶性蛋白向溶酶体的内体运输途径在双突变体中受到干扰，但在单突变体中未受影响。这些液泡运输缺陷通过SKD1的额外表达得以抑制。我们的结果表明，BEACH结构域蛋白SPI除了在P小体中发挥作用外，还在内体运输途径中发挥功能。
