Post-translational processing of pro-opiomelanocortin (POMC)-derived peptides during fetal monkey pituitary development: II. β-lipotropin (β-LPH)-related peptides☆
Post-translational processing of pro-opiomelanocortin (POMC)-derived peptides during fetal monkey pituitary development: II. β-lipotropin (β-LPH)-related peptides☆
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DOI：
10.1016/0012-1606(88)90250-3
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发表时间：
1988-03
影响因子：
2.7
通讯作者：
J. Hatfield;R. G. Allen;J. Stack;O. Rønnekleiv
中科院分区：
文献类型：
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作者：
J. Hatfield;R. G. Allen;J. Stack;O. Rønnekleiv
我们已经研究了POMC衍生肽的翻译后加工过程中胎猴垂体发育免疫分析和反相高效液相色谱法（RP HPLC）。从50天和55天的胎猴和65 - 155天的分离的叶中提取完整的垂体，分级分离，并分析β-促黑素（β-MSH）、中间部分β-内啡肽（β-EP）和乙酰化β-EP的免疫活性。分离的成人垂体叶进行了分析比较。在第50天，通过免疫荧光染色，含有POMC的细胞位于垂体前叶和中间叶，这些细胞大多数位于前叶。第50天和第55天的整个垂体主要含有β-促脂解素（β-LPH）、γ-促脂解素（γ-LPH）、β-EP（1-31）和2.2-kda β-MSH。在第50天的全垂体提取物中未发现乙酰化产物。到第55天，在整个垂体提取物中几乎检测不到羧基缩短和乙酰化的β-EP。这些形式在第65天分离的神经中间叶（NIL）提取物中更明显，并且在第80天与成人比例相似。成人前叶主要含有β-LPH、β-EP和γ-LPH。成年近等基因系几乎只含有2.2kda β-MSH、α-N-乙酰基β-EP（1-31）和α-N-乙酰基β-EP（1-27）。猴NIL中2.2-kda β-LPH的产生表明猴β-LPH与大鼠β-LPH的不同之处在于其必须含有形成2.2-kda β-MSH所需的成对碱性切割位点，而已知大鼠β-LPH中缺乏该位点。另一个发现是猴β-EP在第27位含有Tyr残基，与人β-EP中相同，但似乎在第31位具有大鼠Gln取代。每个叶的翻译后加工模式特征在胎儿中期发育（第80天）时就已明确确立。
We have studied the post-translational processing of POMC-derived peptides during fetal monkey pituitary development using immunoassay and reverse-phase high-performance liquid chromatography (RP HPLC). Whole pituitary glands obtained from Day 50 and 55 fetal monkeys and separated lobes from Day 65 to 155 were extracted, fractionated, and analyzed for β-melanotropin (β-MSH), midportion β-endorphin (β-EP), and acetylated β-EP immunoactivity. Separated adult pituitary lobes were analyzed for comparison. At Day 50, POMC-containing cells were located in both the anterior and intermediate pituitary lobes by immunofluorescence staining, the majority of these cells were localized in the anterior lobe. The Day 50 and 55 whole pituitaries contained predominantly β-lipotropin (β-LPH), γ-lipotropin (γ-LPH), β-EP(1–31), and 2.2-kda β-MSH. No acetylated products were found in Day 50 whole pituitary extracts. By Day 55, carboxy-shortened and acetylated β-EPs were barely detectable in whole pituitary extracts. These forms were more apparent in the Day 65 separated neurointermediate lobe (NIL) extracts, and were similar to adult proportions by Day 80. The adult anterior lobe contained predominantly β-LPH, β-EP, and γ-LPH. Adult NILs contained almost exclusively 2.2-kda β-MSH, α-N-acetyl β-EP(1–31) and α-N-acetyl β-EP(1–27). The production of 2.2-kda β-LPH in the monkey NIL indicates that monkey β-LPH is different from rat β-LPH in that it must contain the paired-basic cleavage site required for the formation of 2.2-kda β-MSH that is known to be lacking in rat β-LPH. Another finding was that monkey β-EP contains a Tyr residue at position 27 as found in human β-EP but appears to have the rat Gln substitution at position 31. The post-translational processing patterns characteristic of each lobe were well established by midterm fetal development (Day 80).