CLONING AND EXPRESSION OF A CYTOSOLIC MEGAKARYOCYTE PROTEIN-TYROSINE-PHOSPHATASE WITH SEQUENCE HOMOLOGY TO RETINALDEHYDE-BINDING PROTEIN AND YEAST SEC14P
CLONING AND EXPRESSION OF A CYTOSOLIC MEGAKARYOCYTE PROTEIN-TYROSINE-PHOSPHATASE WITH SEQUENCE HOMOLOGY TO RETINALDEHYDE-BINDING PROTEIN AND YEAST SEC14P
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DOI：
10.1073/pnas.89.7.2980
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发表时间：
1992-04-01
影响因子：
11.1
通讯作者：
MAJERUS, PW
中科院分区：
文献类型：
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作者：
GU, MX;WARSHAWSKY, I;MAJERUS, PW
蛋白质酪氨酸磷酸化在细胞生长、细胞周期和恶性转化的调节中很重要。 我们从 MEG-01 细胞和人脐静脉内皮细胞 cDNA 文库中克隆了编码胞浆蛋白酪氨酸磷酸酶 (PTPase) MEG2 的 cDNA。 PTPase MEG2 的 4-kilobase cDNA 序列的长度与 Northern blotting 检测到的 mRNA 转录物的长度相对应。 预测的开放阅读框编码由 593 个氨基酸组成的 68 kDa 蛋白质，没有明显的信号或跨膜序列，表明它是一种胞质蛋白。 C 末端区域具有 PTPase 催化结构域，与其他已知的 PTPase 具有 30-40% 的氨基酸同一性。 N 末端区域有 254 个氨基酸，与细胞视黄醛结合蛋白 28% 相同，与酵母 SEC14p 相同 24%，SEC14p 是一种具有磷脂酰肌醇转移活性的蛋白质，是酵母中通过高尔基复合体分泌蛋白质所必需的。 在大肠杆菌中表达的重组 PTPase MEG2 具有 PTPase 活性。 在测试的 12 个细胞系中检测到 PTPase MEG2 mRNA，这表明这种磷酸酶广泛表达。 PTPase MEG2 的结构表明酪氨酸磷酸酶可以参与疏水性配体的转移或高尔基体的功能。
Protein tyrosine phosphorylation is important in the regulation of cell growth, the cell cycle, and malignant transformation. We have cloned a cDNA that encodes a cytosolic protein-tyrosine-phosphatase (PTPase), MEG2, from MEG-01 cell and human umbilical vein endothelial cell cDNA libraries. The 4-kilobase cDNA sequence of PTPase MEG2 corresponds in length to the mRNA transcript detected by Northern blotting. The predicted open reading frame encodes a 68-kDa protein composed of 593 amino acids and has no apparent signal or transmembrane sequences, suggesting that it is a cytosolic protein. The C-terminal region has a PTPase catalytic domain that has 30-40% amino acid identity to other known PTPases. The N-terminal region has 254 amino acids that are 28% identical to cellular retinaldehyde-binding protein and 24% identical to yeast SEC14p, a protein that has phosphatidylinositol transfer activity and is required for protein secretion through the Golgi complex in yeast. Recombinant PTPase MEG2 expressed in Escherichia coli possesses PTPase activity. PTPase MEG2 mRNA was detected in 12 cell lines tested, which suggests that this phosphatase is widely expressed. The structure of PTPase MEG2 implies that a tyrosine phosphatase could participate in the transfer of hydrophobic ligands or in functions of the Golgi apparatus.