This study aimed to investigate for the first time, the profile of Physarum microplasmodial phosphatase (PPH) activity toward the phosphorylated light chain of Physarum myosin II (PLCM) at pH 7.6, the velocity of cytoplasmic streaming, and PPH expression in spherule formation during dark starvation (DS). In this study, we cloned the full-length cDNA of PPH using polymerase chain reaction, based on the N-terminal amino acid sequence of the purified enzyme. The cDNA contained an open reading frame (ORF) of 1245 bp, corresponding to 415 amino acids. We confirmed that a rapid increase in PPH activity toward PLCM and a rapid decrease in cytoplasmic streaming velocity precede spherule formation by Physarum microplasmodia. The profiles of increase in PPH activity toward PLCM, PPH expression, and PPH accumulation during DS were correlated with spherule formation in the Physarum microplasmodia. Moreover, application of the wheat germ cell-free expression system resulted in the successful production of recombinant PPH and in the expression of phosphatase activity toward PLCM. These results suggest that PPH is involved in the cessation of cytoplasmic streaming in Physarum microplasmodia during DS.

中文翻译：

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对细胞质流和小球形成至关重要的微囊藻磷酸酶活性的概况。

这项研究的目的是首次调查在黑暗中，Physarum微浆磷酸酶（PPH ）在pH 7.6时对Physarum myosin II（PLCM）磷酸化轻链的活性，胞质流的速度以及PPH在小球形成中的表达情况。饥饿（DS）。在这项研究中，我们基于聚合酶的N末端氨基酸序列，使用聚合酶链反应克隆了PPH的全长cDNA。cDNA包含一个1245 bp的开放阅读框（ORF），对应于415个氨基酸。我们证实，迅速增加对PLCM PPH活动，并通过在细胞质流速度普瑞森小球形成的迅速下降绒泡微胞浆菌。在PPH活动朝向PLCM，增加的轮廓PPH表达和积累PPH DS期间与在小球形成有相关性绒泡microplasmodia。此外，小麦无细胞表达系统的应用导致重组PPH的成功生产和对PLCM的磷酸酶活性的表达。这些结果表明，在DS期间，PPH参与了Physarum microplasmodia中胞浆流的停止。