Chemical genetic screening identifies sulfonamides that raise organellar pH and interfere with membrane traffic
Chemical genetic screening identifies sulfonamides that raise organellar pH and interfere with membrane traffic
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DOI：
10.1111/j.1398-9219.2004.00193.x
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发表时间：
2004-07-01
期刊：
影响因子：
4.5
通讯作者：
Wessling-Resnick, M
中科院分区：
文献类型：
--
作者：
Nieland, TJF;Feng, Y;Wessling-Resnick, M
化学遗传学旨在鉴定提供细胞生物学途径功能解剖的小分子。先前对胞吐膜运输的小分子抑制剂的筛选产生了阻断从高尔基体到细胞表面的运输以及从内质网到高尔基体网络的运输的几种化合物的鉴定和表征[Feng等人，Proc Natl Acad Sci USA 2003;100：6469-6474; Yarrow等人，Comb Chem High Lipput Screen 2003;6：279-286; Feng等人，EMBO Reports 2004：in press]。在这里，我们筛选这些抑制剂对内吞膜交通的潜在影响。两种结构相关的磺胺类药物被发现是转铁蛋白介导的铁摄取的有效和可逆的抑制剂。这些抑制剂不阻断内质网到高尔基体的运输，但破坏高尔基体到细胞表面的运输。这些化合物是一类新的磺胺类药物的成员，这些磺胺类药物升高内体和溶酶体pH，下调细胞表面受体，并损害内化的转铁蛋白受体向质膜的再循环。体外实验表明，磺胺类药物直接抑制V-ATP酶对三磷酸腺苷（ATP）的水解，并且它们还具有有效的质子离子载体活性。虽然细胞器pH值的维持已知是内吞作用和胞吐作用的关键因素，但除了配体与其受体解偶联之外，酸化的确切作用在很大程度上仍然未知。这类新的磺胺类抑制剂的鉴定提供了新的化学工具，以更好地了解细胞器pH值在膜交通和V-ATP酶的活性，特别是功能。
Chemical genetics seeks to identify small molecules that afford functional dissection of cell biological pathways. Previous screens for small molecule inhibitors of exocytic membrane traffic yielded the identification and characterization of several compounds that block traffic from the Golgi to the cell surface as well as transport from the endoplasmic reticulum to the Golgi network [Feng et al. Proc Natl Acad Sci USA 2003;100:6469-6474; Yarrow et al. Comb Chem High Throughput Screen 2003;6:279-286; Feng et al. EMBO Reports 2004: in press]. Here, we screened these inhibitors for potential effects on endocytic membrane traffic. Two structurally related sulfonamides were found to be potent and reversible inhibitors of transferrin-mediated iron uptake. These inhibitors do not block endoplasmic reticulum-to-Golgi transport, but do disrupt Golgi-to-cell surface traffic. The compounds are members of a novel class of sulfonamides that elevate endosomal and lysosomal pH, down-regulate cell surface receptors, and impair recycling of internalized transferrin receptors to the plasma membrane. In vitro experiments revealed that the sulfonamides directly inhibit adenosine triphosphate (ATP) hydrolysis by the V-ATPase and that they also possess a potent proton ionophore activity. While maintenance of organellar pH is known to be a critical factor in both endocytosis and exocytosis, the precise role of acidification, beyond the uncoupling of ligands from their receptors, remains largely unknown. Identification of this novel class of sulfonamide inhibitors provides new chemical tools to better understand the function of organelle pH in membrane traffic and the activity of V-ATPases in particular.