Decreased heat sensitivity of lungfish TRPV1 revealed by the heterologous expression system
Decreased heat sensitivity of lungfish TRPV1 revealed by the heterologous expression system
复制标题
异源表达系统揭示肺鱼TRPV1热敏感性降低
DOI：
10.1016/j.bbrc.2023.01.060
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Osamu Saitoh
中科院分区：
文献类型：
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作者：
Shogo Hori;Osamu Saitoh
本研究以非洲肺鱼Protopterusannectens的TRPV1为研究对象。在高温干旱时期，非洲肺鱼可以通过在泥茧中夏眠来生存。因此，肺鱼被认为具有一些专门的热传感器 TRPV1，用于耐热。此外，肺鱼与鱼类和两栖动物有相似之处，是研究鱼类向四足动物转变的重要物种之一。由于鱼类TRPV1与四足动物TRPV1存在一定差异，肺鱼TRPV1的特性引起人们的关注。在这里，我们首先从肺鱼Protopterus annectens中克隆了TRPV1旁系同源物（lfTRPV1），并利用青蛙卵母细胞通过两电极电压钳法测定了lfTRPV1的化学和热敏感性。我们检测到酸和 2-APB 激活 lfTRPV1，但未观察到辣椒素诱导的激活。 lfTRPV1对酸的敏感性与大鼠TRPV1(rTRPV1)相似，但lfTRPV1对2-APB的敏感性相对弱于rTRPV1。高达 44°C 的热刺激不会激活 lfTRPV1，即使在 pH6 的酸性条件下也未检测到热激活。 TRPV1 热敏感性的显着降低可能有助于非洲肺鱼的耐热性。此外，这可能是古代四足动物型TRPV1基因的特性。
In this study, we focused on TRPV1 of African lungfish,Protopterusannectens.During drought at high temperature, African lungfish can survive by undergoing into aestivation in mud cocoons. Therefore, lungfish is considered to have some specialized heat-sensor, TRPV1, for heat tolerance. Further, lungfish which shares similarities with fishes and amphibians, is one of important species for investigating the fish-tetrapod transition. Since fish TRPV1 and tetrapod TRPV1 have some differences, character of lungfish TRPV1 attracts attention. Here, we first cloned TRPV1 paralogue from lungfish,Protopterus annectens(lfTRPV1) and determined the chemical and thermal sensitivities of lfTRPV1 by two-electrode voltage clamp method using frog oocytes. We detected activation of lfTRPV1 by acid and 2-APB, but capsaicin-induced activation was not observed. The sensitivity to acid of lfTRPV1 was similar to that of rat TRPV1 (rTRPV1), but the 2-APB sensitivity of lfTRPV1 was relatively weaker than rTRPV1. Heat stimulation up to 44 °C did not activate lfTRPV1 and the heat-activation was not detected even on acid condition of pH6. This dramatically decreased heat-sensitivity of TRPV1 may contribute the heat tolerance of African lungfish. Moreover, this might be the property of ancient tetrapod-type TRPV1 gene.