Role of tyrosine residues in modulation of claudin-4 by the C-terminal fragment of Clostridium perfringens enterotoxin
Role of tyrosine residues in modulation of claudin-4 by the C-terminal fragment of Clostridium perfringens enterotoxin
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DOI：
10.1016/j.bcp.2006.10.002
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发表时间：
2007-01-15
影响因子：
5.8
通讯作者：
Watanabe, Yoshiteru
中科院分区：
文献类型：
--
作者：
Harada, Motoki;Kondoh, Masuo;Watanabe, Yoshiteru
产气荚膜梭菌肠毒素（C-CPE）的C-末端片段通过其C-末端16个氨基酸调节claudin-4的屏障功能。在本研究中，我们调查的作用酪氨酸残基（Y306，Y310和Y312）在该区域的调制TJ的C-CPE。将Y306、Y310和Y312单突变为丙氨酸导致紧密连接蛋白-4结合的部分减少。我们还制备了C-CPE的双突变体，以进一步评估这些酪氨酸残基的作用。用丙氨酸替换Y310和Y312（Y310 A/Y312 A）部分地降低了C-CPE结合封闭蛋白-4的能力。然而，双突变体Y306 A/Y310 A和Y306 A/Y312 A丧失了与密蛋白-4结合和调节TJ屏障的能力。我们还发现，三重突变体（Y306 A/Y310 A/Y312 A）失去了结合claudin-4的能力，调节TJ屏障，并增强大鼠空肠吸收。这些结果表明，酪氨酸306、310和312对于C-CPE与密蛋白-4的相互作用和C-CPE对TJ屏障功能的调节是关键的。这项研究提供的信息，应该有助于开发基于C-CPE的claudin调节剂。(c)2006年爱思唯尔公司All rights reserved.
The C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE) modulates the barrier function of claudin-4 via its C-terminal 16 amino acids. In the current study, we investigated the roles of tyrosine residues (Y306, Y310 and Y312) in this region in the modulation of TJs by C-CPE. Single mutations of Y306, Y310 and Y312 to alanine resulted in partial reduction of claudin-4 binding. We also prepared double mutants of C-CPE to further evaluate the roles of these tyrosine residues. Replacement of Y310 and Y312 with alanine (Y310A/Y312A) partly reduced the ability of C-CPE to bind to claudin-4. Double mutants Y306A/Y310A and Y306A/ Y312A, however, lost the ability to bind to claudin-4 and to modulate the TJ barrier. We also found that a triple mutant (Y306A/Y310A/Y312A) lost the ability to bind claudin-4, modulate the TJ barrier, and enhance jejunal absorption in rats. These results indicate that tyrosines 306, 310, and 312 are critical for the interaction of C-CPE with claudin-4 and for the modulation of TJ barrier function by C-CPE. This study provides information that should help in the development of claudin modulators based on C-CPE. (c) 2006 Elsevier Inc. All rights reserved.