PTPIP51-a myeloid lineage specific protein interacts with PTP1B in neutrophil granulocytes
PTPIP51-a myeloid lineage specific protein interacts with PTP1B in neutrophil granulocytes
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DOI：
10.1016/j.bcmd.2010.04.009
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发表时间：
2010-08-15
影响因子：
2.3
通讯作者：
Wimmer, Monika
中科院分区：
文献类型：
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作者：
Brobeil, Alexander;Graf, Michaela;Wimmer, Monika
蛋白酪氨酸磷酸酶相互作用蛋白51（PTPIP 51）是蛋白酪氨酸磷酸酶1B（PTP 1B）和T细胞蛋白酪氨酸磷酸酶（TCPTP）的体外相互作用伴侣。PTPIP 51的全长形式包括470 aas，并且具有52 kDa的分子量。生理功能知之甚少，但参与分化过程和细胞凋亡已被提出。初步观察表明血细胞中PTPIP 51表达的差异。为了分析PTPIP 51在造血过程中的可能参与，我们研究了其在外周静脉血（PVB）、脐带血（UCB）和人骨髓（HBM）样品中的表达。在两者中，PVB和UCB PTPIP 51表达仅限于中性粒细胞。在HBM样本中，除了在成熟的中性粒细胞中，PTPIP 51蛋白和mRNA存在于中性粒细胞的髓样前体细胞中。通过免疫印迹分析证实PTPIP 51在中性粒细胞中的表达，显示不同分子量形式的PTPIP 51蛋白。识别PTPIP 51蛋白的特定区域（C-末端、N-末端和aas 114 -129）的抗肽抗体揭示了不同来源的中性粒细胞中的不同同种型表达模式。在PVB和UCB中性粒细胞反应阳性的所有三种肽抗体。而HBM中性粒细胞仅表达PTPIP 51蛋白的N端变体，缺少C端和aas 114 -129序列，免疫细胞化学结果显示PTPIP 51和PTP 1B在PVB和UCB中严格共定位。两种蛋白质的相互作用通过邻位连接测定来验证。无论是增殖细胞，PCNA免疫染色，也不是凋亡细胞，TUNEL法标记，显示PTPIP 51在HBM的免疫反应性。事实上，PTPIP 51表达仅限于正在分化的髓样前体细胞。因此，在血细胞中，PTPIP 51的表达仅限于分化和成熟的中性粒细胞。(C)2010年爱思唯尔公司All rights reserved.
Protein tyrosine phosphatase interacting protein 51 (PTPIP51) was identified as an in vitro interacting partner of protein tyrosine phosphatase 1B (PTP1B) and T-cell protein tyrosine phosphatase (TCPTP). The full-length form of PTPIP51 encompasses 470aas and has a molecular weight of 52 kDa. The physiological function is poorly understood but an involvement in differentiation processes and apoptosis has been suggested. Preliminary observations suggested differences in PTPIP51 expression in blood cells. To analyze a possible involvement of PTPIP51 in hematopoietic processes, we studied its expression in samples of peripheral venous blood (PVB), umbilical cord blood (UCB) and human bone marrow (HBM). In both, PVB and UCB PTPIP51 expression was restricted to neutrophil granulocytes. In HBM samples, besides in mature neutrophil ganulocytes PTPIP51 protein and mRNA was present in myeloid precursor cells of neutrophils. The expression of PTPIP51 in neutrophil granulocytes was corroborated by immunoblot analysis exhibiting different molecular weight forms of PTPIP51 protein. Anti-peptide antibodies, identifying specific regions of the PTPIP51 protein (C-terminus, N-terminus and aas114-129) revealed a distinct isoform expression pattern in neutrophil granulocytes of different sources. In PVB and UCB neutrophil granulocytes reacted positive for all three peptide antibodies. In contrast, neutrophils of HBM express solely an N-terminal variant of PTPIP51 protein, lacking the C-terminal and aas114-129 sequence.Immunocytochemical results displayed a strict co-localization of PTPIP51 and PTP1B in PVB and UCB. The interaction of both proteins was verified by a proximity ligation assay. Neither proliferating cells, as identified by PCNA immunostaining, nor apoptotic cells, labeled by TUNEL assay, displayed an immunoreactivity for PTPIP51 in HBM. In fact, PTPIP51 expression was restricted to myeloid precursor cells undergoing differentiation. In blood cells therefore, PTPIP51 expression is restricted to differentiating and mature neutrophil granulocytes. (C) 2010 Elsevier Inc. All rights reserved.