Institute of Interfacial Process Engineering and Plasma Technology, University of Stuttgart, Stuttgart, Germany.
Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts, United States of America.
PLoS One. 2018 Aug 6;13(8):e0201932. doi: 10.1371/journal.pone.0201932. eCollection 2018.
Members of the Cysteine-rich secretory protein, Antigen 5 and Pathogenesis-related 1 (CAP) protein superfamily are important virulence factors in fungi but remain poorly characterized on molecular level. Here, we investigate the cellular localization and molecular function of Rbe1p and Rbt4p, two CAP family members from the human pathogen Candida albicans. We unexpectedly found that Rbe1p localizes to budding sites of yeast cells in a disulfide bond-dependent manner. Furthermore, we show that Rbe1p and Rbt4p bind free cholesterol in vitro and export cholesteryl acetate in vivo. These findings suggest a previously undescribed role for Rbe1p in cell wall-associated processes and a possible connection between the virulence attributes of fungal CAP proteins and sterol binding.
富含半胱氨酸的分泌蛋白、抗原 5 和与发病机制相关蛋白 1 (CAP) 蛋白超家族的成员是真菌中重要的毒力因子，但在分子水平上的研究仍很不完善。在这里，我们研究了人类病原体白色念珠菌中两个 CAP 家族成员 Rbe1p 和 Rbt4p 的细胞定位和分子功能。我们出人意料地发现，Rbe1p 以二硫键依赖的方式定位于酵母细胞的出芽部位。此外，我们还表明，Rbe1p 和 Rbt4p 在体外结合游离胆固醇，并在体内输出胆固醇乙酸酯。这些发现表明 Rbe1p 在细胞壁相关过程中具有以前未描述的作用，以及真菌 CAP 蛋白的毒力特性与固醇结合之间可能存在联系。
