DLG-1 is a MAGUK similar to SAP97 and is required for adherens junction formation
DLG-1 is a MAGUK similar to SAP97 and is required for adherens junction formation
复制标题
DOI：
10.1091/mbc.12.11.3465
复制
发表时间：
2001-11-01
影响因子：
3.3
通讯作者：
Rongo, C
中科院分区：
文献类型：
--
作者：
Firestein, BL;Rongo, C
细胞连接对于细胞间通讯和细胞组装成组织至关重要。细胞连接通常由紧密连接和粘附连接组成，紧密连接形成渗透性屏障并防止脂质和蛋白质在细胞隔室之间扩散，粘附连接控制细胞的粘附并将皮质肌动蛋白丝连接到质膜上的附着位点。正确的紧密连接形成和细胞极性需要包含PDZ蛋白-蛋白相互作用结构域的膜相关鸟苷酸激酶（MAGUKs）的功能。相比之下，关于粘附连接是如何组装的知之甚少。在这里，我们描述了如何PDZ含蛋白DLG-1所需的正确形成和功能的粘附连接在秀丽隐杆线虫。DLG-1是MAGUK蛋白，其在序列上与哺乳动物SAP 97最相似，SAP 97在CNS的突触以及上皮细胞的细胞连接处都有发现。DLG-1定位于粘附连接处，并且DLG-1定位由与SAP 97共享但在其他MAGUK家族成员中未发现的氨基末端结构域介导。DLG-1招募其他蛋白质和信号分子到粘附连接，而缺乏DLG-1的胚胎无法招募蛋白质AJM-1和CPI-1到粘附连接。DLG-1是肌动蛋白细胞骨架的适当组织所必需的。以及胚胎的形态伸长。与已观察到影响粘附连接组装和功能的其他蛋白质相反，DLG-1不需要维持细胞极性。我们的研究结果表明，MAGUK蛋白的新功能不同于它们在细胞极性中的作用。
Cellular junctions are critical for intercellular communication and for the assembly of cells into tissues. Cell junctions often consist of tight junctions, which form a permeability barrier and prevent the diffusion of lipids and proteins between cell compartments, and adherens junctions, which control the adhesion of cells and link cortical actin filaments to attachment sites on the plasma membrane. Proper tight junction formation and cell polarity require the function of membrane-associated guanylate kinases (MAGUKs) that contain the PDZ protein-protein interaction domain. In contrast, less is known about how adherens junctions are assembled. Here we describe how the PDZ-containing protein DLG-1 is required for the proper formation and function of adherens junctions in Caenorhabditis elegans. DLG-1 is a MAGUK protein that is most similar in sequence to mammalian SAP97, which is found at both synapses of the CNS, as well as at cell junctions of epithelia. DLG-1 is localized to adherens junctions, and DLG-1 localization is mediated by an amino-terminal domain shared with SAP97 but not found in other MAGUK family members. DLG-1 recruits other proteins and signaling molecules to adherens junctions, while embryos that lack DLG-1 fail to recruit the proteins AJM-1 and CPI-1 to adherens junctions. DLG-1 is required for the proper organization of the actin cytoskeleton. and for the morphological elongation of embryos. In contrast to other proteins that have been observed to affect adherens junction assembly and function, DLG-1 is not required to maintain cell polarity. Our results suggest a new function for MAGUK proteins distinct from their role in cell polarity.