Center for Tropical and Emerging Global Diseases, University of Georgia, Athens, Georgia.
Department of Cellular Biology, University of Georgia, Athens, Georgia.
Microbiol Spectr. 2024 Nov 5;12(11):e0112824. doi: 10.1128/spectrum.01128-24. Epub 2024 Oct 9.
Acidocalcisomes of are membrane-bounded organelles characterized by their acidity and high content of polyphosphate and cations, like calcium and magnesium. They have important roles in cation and phosphorus storage, osmoregulation, autophagy initiation, calcium signaling, and virulence. Acidocalcisomes of possess several membrane transporters, pumps, and channels, some of which were identified by proteomic and immunofluorescence analyses and validated as acidocalcisome proteins by their colocalization with the acidocalcisome marker vacuolar proton pyrophosphatase (VP1). Here, we report that a set of membrane transporters and enzymes, which were proposed to be present in acidocalcisomes by the morphological appearance of tagged proteins, colocalize with VP1, validating their character as acidocalcisome proteins.
Acidocalcisomes are acidic organelles rich in polyphosphate and calcium present in a variety of eukaryotes and important for osmoregulation and calcium signaling. Several proteins were postulated to localize to acidocalcisomes based on their morphological characteristics. We provide validation of the localization of ten10 acidocalcisome proteins by their co-localization with enzymatic markers. These findings reveal the roles of acidocalcisomes in the storage of toxic metals, and the presence of enzymes involved in palmitoylation and polyphosphate metabolism.
是一种具有膜结合特征的细胞器，其特点是酸性、多磷酸盐和阳离子（如钙和镁）含量高。它们在阳离子和磷储存、渗透调节、自噬起始、钙信号转导和毒力方面发挥着重要作用。的酸钙小体具有几种膜转运蛋白、泵和通道，其中一些通过蛋白质组学和免疫荧光分析鉴定，并通过与酸钙小体标记物液泡质子焦磷酸酶（VP1）的共定位来验证为酸钙小体蛋白。在这里，我们报告了一组膜转运蛋白和酶，它们被形态学上标记蛋白的出现推测存在于酸钙小体中，与 VP1 共定位，验证了它们作为酸钙小体蛋白的特征。
重要性：酸钙小体是一种富含多磷酸盐和钙的酸性细胞器，存在于多种真核生物中，对渗透调节和钙信号转导很重要。一些蛋白质根据其形态特征被推测定位于酸钙小体。我们通过与酶标记物的共定位来验证 ten10 种酸钙小体蛋白的定位。这些发现揭示了酸钙小体在储存有毒金属以及参与棕榈酰化和多磷酸盐代谢的酶方面的作用。
