Interaction of the bullous pemphigoid antigen 1 (BP230) and desmoplakin with intermediate filaments is mediated by distinct sequences within their COOH terminus
Interaction of the bullous pemphigoid antigen 1 (BP230) and desmoplakin with intermediate filaments is mediated by distinct sequences within their COOH terminus
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DOI：
10.1091/mbc.e02-08-0548
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发表时间：
2003-05-01
影响因子：
3.3
通讯作者：
Borradori, L
中科院分区：
文献类型：
--
作者：
Fontao, L;Favre, B;Borradori, L
大疱性类天疱疮抗原I （BP230）和desmoplakin PP)是血小板蛋白家族细胞连接物的成员。尽管它们具有同源性，但它们的COOH末端选择性地结合不同的中间丝（if）。我们通过酵母三杂交、细胞转染和覆盖实验研究了它们与表皮角蛋白K5/K14、简单上皮角蛋白K8/K18和III型IF波形蛋白相互作用所需的COOH末端序列。结果表明，BP230与K5/K14相互作用，但不与K8/K18或vimentin相互作用，通过包含B和C亚结构域和COOH末端的区域，包括COOH末端的8个氨基酸延伸。与此相反，位于DP cooh末端的C亚域与K5/K14和K8/K18相互作用，其连接区域能够与K8/K18和vimentin相互作用。此外，酵母中DP与IF蛋白相互作用的潜力似乎受到其COOH末端Ser 2849磷酸化的调节。引人注目的是，BP230和DP仅在I型和H型角蛋白同时存在时才与细胞角蛋白相互作用。K5/K14角蛋白的头部和尾部结构域对于它们与BP230或DP的相互作用是不可缺少的。根据我们的研究结果，我们假设：(1)斑块对各种IF蛋白的结合特异性取决于它们在高度同源的B和C亚结构域及其COOH末端之间的连接区域；(2)DP和BP230与表皮和简单角蛋白的关联受到异源二聚化诱导的三级结构的严重影响，并涉及主要位于这些角蛋白杆结构域的识别位点。
The bullous pemphigoid antigen I (BP230) and desmoplakin PP) are members of the plakin protein family of cytolinkers. Despite their homology, their COOH termini selectively bind distinct intermediate filaments (IFs). We studied sequences within their COOH termini required for their interaction with the epidermal keratins K5/K14, the simple epithelial keratins K8/K18, and type III IF vimentin by yeast three-hybrid, cell transfection, and overlay assays. The results indicate that BP230 interacts with K5/K14 but not with K8/K18 or vimentin via a region encompassing both the B and C subdomains and the COOH extremity, including a COOH-terminal eight amino-acid stretch. In contrast, the C subdomain with the COOH-terminal extremity of DP interacts with K5/K14 and K8/K18, and its linker region is able to associate with K8/K18 and vimentin. Furthermore, the potential of DP to interact with IF proteins in yeast seems to be regulated by phosphorylation of Ser 2849 within its COOH terminus. Strikingly, BP230 and DP interacted with cytokeratins only when both type I and type H keratins were present. The head and tail domains of K5/K14 keratins were dispensable for their interaction with BP230 or DP. On the basis of our findings, we postulate that (1) the binding specificity of plakins for various IF proteins depends on their linker region between the highly homologous B and C subdomains and their COOH extremity and (2) the association of DP and BP230 with both epidermal and simple keratins is critically affected by the tertiary structure induced by heterodimerization and involves recognition sites located primarily in the rod domain of these keratins.