Merchenthaler I, Meeker M, Petrusz P, Kizer J S
Department of Anatomy, University Medical School, Pecs, Hungary.
Endocrinology. 1989 Apr;124(4):1888-97. doi: 10.1210/endo-124-4-1888.
Antisera were raised to a tridecapeptide, Ser-Asp-Val-Thr-Lys-Arg-Gln-His-Pro-Gly-Arg-Arg-Phe, that was synthesized based on the sequence (residues 166-178) of a proposed cDNA for pro-TRH reported by Lechan et al. With this antiserum, immunostaining of Western blots of rat brain extracts revealed two major proteins with mol wt (Mr = 39,000 and 52,000) considerably larger than that of the largest protein (Mr = 29,000) that could be encoded by the cDNA of Lechan et al. Because these observations suggested the possibility of novel TRH precursors, we studied the immunocytochemical distribution of pro-TRH (39-52K) in rat brain. Our anatomical findings were 4-fold. 1) The distributions of 29K pro-TRH and 39-52K pro-TRH are not identical. 2) TRH is found only in regions containing 29K pro-TRH, 39-52K pro-TRH, or both. 3) There are regions that contain both 29K pro-TRH and 39-52K pro-TRH, but no TRH. 4) Regions containing only 39-52K pro-TRH do not contain 29K pro-TRH mRNA as mapped by Segerson et al. From these electrophoretic and anatomical observations, we postulate the existence of at least one and possibly two additional precursors that can be processed to TRH in rat brain.
针对一种十三肽（Ser - Asp - Val - Thr - Lys - Arg - Gln - His - Pro - Gly - Arg - Arg - Phe）制备了抗血清，该十三肽是根据Lechan等人报道的促甲状腺激素释放激素原（pro - TRH）的推测cDNA序列（第166 - 178位氨基酸残基）合成的。用这种抗血清对大鼠脑提取物进行蛋白质免疫印迹分析时，发现有两种主要蛋白质，其分子量（Mr = 39,000和52,000）比Lechan等人cDNA所能编码的最大蛋白质（Mr = 29,000）大得多。由于这些观察结果提示可能存在新型的TRH前体，我们研究了大鼠脑中pro - TRH（39 - 52K）的免疫细胞化学分布。我们的解剖学发现有四点：1）29K的pro - TRH和39 - 52K的pro - TRH分布不同。2）TRH仅在含有29K的pro - TRH、39 - 52K的pro - TRH或两者都有的区域中发现。3）存在同时含有29K的pro - TRH和39 - 52K的pro - TRH但没有TRH的区域。4）仅含有39 - 52K的pro - TRH的区域不含有Segerson等人绘制的29K的pro - TRH mRNA。基于这些电泳和解剖学观察结果，我们推测在大鼠脑中至少存在一种，也可能存在另外两种可加工成TRH的前体。
