Molecular cloning and chromosome mapping of the human gene encoding protein phosphotyrosyl phosphatase 1B.

Brown-Shimer, Sheryl; Johnson, Karen A.; Lawrence, Jeanne B.; Johnson, Carol V.; Bruskin, Arthur M.; Green, Nancy R.; Hill, David E.

doi:10.1073/pnas.87.13.5148

Cited by 168 publications

(105 citation statements)

References 45 publications

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“…The polymerase chain reaction was used to obtain the coding region of PTPlB with placental poly(A)-rich RNA as template (Brown-Shimer et al, 1990). Convenient restriction sites were introduced in the primers to facilitate subsequent cloning : the S'oligonucleotide included a BamHI site upstream of the initiation codon followed by an NcoI site which included the first ATG, and the 3'oligonucleotide contained an XbaI site downstream of the termination codon.…”

Section: Construction Of Ptplb Expression Plasmidsmentioning

confidence: 99%

Expression, purification and crystallization of human phosphotyrosine phosphatase 1B

Hoppe

Berne

Stock

et al. 1994

European Journal of Biochemistry

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Protein phosphotyrosine phosphatases are believed to be involved in the regulation of the activity of cellular proteins, such as receptor tyrosine kinases, by controlling their phosphorylation status. One of the best described and characterized protein of this class of enzymes is the phosphotyrosine phosphatase 1B. To obtain sufficient quantities for structural investigations, truncated forms of PTPlB encompassing the catalytic domain were over-expressed in Escherichia coli and purified to apparent homogeneity by conventional chromatography. The activity of these purified enzymes has been compared with the wild-type enzyme expressed in mammalian cells. By measuring the activities against p-nitrophenyl phosphate, the pH dependence of this activity, and responses to different modulators, it could be demonstrated that the truncated forms of PTPlB retained the same characteristics as the full-length mammalian enzyme, but are not subject to inhibition of enzymic activity mediated by the C-terminus. Due to their improved solubility, it can be assumed that the catalytic domains are advantageous for crystallization studies in comparison to the natural enzyme. In a screening for crystallization conditions, we obtained protein crystals indicating that the quality of the purified protein is sufficient for crystallographic studies.

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Section: Construction Of Ptplb Expression Plasmidsmentioning

confidence: 99%

Expression, purification and crystallization of human phosphotyrosine phosphatase 1B

Hoppe

Berne

Stock

et al. 1994

European Journal of Biochemistry

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“…Another PTP that has been implicated in integrin signaling is protein tyrosine phosphatase 1B (PTP-1B), the first PTP that was identified and cloned (22)(23)(24)(25)(26). Its structure consists of an N-terminal catalytic domain followed by two tandem prolinerich motifs that possess a consensus for binding to proteins with SH3 domains (27).…”

mentioning

confidence: 99%

Attenuation of Adhesion-dependent Signaling and Cell Spreading in Transformed Fibroblasts Lacking Protein Tyrosine Phosphatase-1B

Cheng

Bal

Kennedy

et al. 2001

Journal of Biological Chemistry

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Previous biochemical evidence has yielded conflicting models for the role of protein tyrosine phosphatase-1B (PTP-1B) in the regulation of integrin signaling. Thus, to establish the physiological relevance for such a role, we employed a genetic approach by generating embryonic fibroblasts from PTP-1B knockout mice. Both primary fibroblasts and their derived cell lines were used in this study. Immortalization of wild-type primary cells with the SV40 Large T antigen resulted in a dramatic increase in the endogenous expression of PTP-1B, suggesting a role during transformation. Moreover, the absence of PTP-1B in the transformed cell lines led to a more pronounced effect on different pathways of fibronectin-mediated signaling compared with the untransformed state. Specifically, p130Cas phosphorylation, Erk activation as well as cell spreading were delayed in PTP-1B-deficient cells, compared with their wild-type counterparts. Interestingly, this attenuation in integrin-mediated events closely resembles that of Src-deficient fibroblasts. Indeed, PTP-1B deficient, transformed fibroblasts held in suspension do exhibit a hyperphosphorylation of the inhibitory site (Tyr-527) of Src, compared with their wild-type counterparts. These results establish PTP-1B as a positive physiological regulator of integrin signaling in transformed cells, acting upstream of Src Tyr-527 dephosphorylation that leads to several adhesion-dependent events.

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“…The founding member of its family, protein tyrosine phosphatase 1B (PTP1B) 1,2 (the protein product of the gene PTPN1 3 ) is an important regulator of phosphotyrosine signaling in mammalian cells through its dephosphorylation of a range of substrates 4 , including the receptors for insulin, leptin, and epidermal growth factor (EGF) and their downstream substrates; the tyrosine kinases JAK2 and c-Src; and the tyrosine phosphatase SHP2. PTP1B expression has been detected in several tissues in different mammals 5 and has been proposed as an important inhibitory target for treatment of diabetes, obesity, and cancer 6 .…”

Section: Introductionmentioning

confidence: 99%

Journey to the Center of the Mitochondria Guided by the Tail Anchor of Protein Tyrosine Phosphatase 1B

Fueller

Egorov

et al. 2013

Preprint

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The canonical protein tyrosine phosphatase PTP1B has traditionally been considered to exclusively reside on the endoplasmic reticulum (ER). Using confocal microscopy, we show that endogenous PTP1B actually exhibits a higher local concentration at the mitochondria in all mammalian cell lines that we tested. Fluorescently labeled chimeras containing full-length PTP1B or only its 35 amino acid tail anchor localized identically, demonstrating the complete dependence of PTP1B's subcellular partitioning on its tail anchor. Correlative light and electron microscopy using GFPdriven photo-oxidation of DAB revealed that PTP1B's tail anchor localizes it to the mitochondrial interior and to mitochondrial-associated membrane (MAM) sites along the ER. Heterologous expression of the tail anchor of PTP1B in the yeast S. cerevisiae surprisingly led to its exclusive localization to the ER/vacuole with no presence at the mitochondria. Studies with various yeast mutants of conserved membrane insertion pathways revealed a role for the GET/TRC40 pathway in ER insertion, but also emphasized the likely dominant role of spontaneous insertion. Further studies of modified tail isoforms in both yeast and mammalian cells revealed a remarkable sensitivity of subcellular partitioning to slight changes in transmembrane domain (TMD) length, C-terminal charge, and hydropathy. For example, addition of a single positive charge to the tail anchor was sufficient to completely shift the tail anchor to the mitochondria in mammalian cells and to largely shift it there in yeast cells, and a point mutation that increased TMD hydropathy was sufficient to localize the tail anchor exclusively to the ER in mammalian cells. Striking differences in the subcellular partitioning of a given tail anchor isoform in mammalian versus yeast cells most likely point to fundamental differences in the lipid composition of specific organelles (e.g. affecting membrane charge or thickness) in higher versus lower eukaryotes. Fluorescence lifetime imaging microscopy (FLIM) detection of the Förster Resonance Energy Transfer (FRET)-based interaction of the catalytic domain of PTP1B with the epidermal growth factor receptor (EGFR/ErbB1) at the mitochondria revealed a strong interaction on the cytosolic face of the outer mitochondrial membrane (OMM), suggesting the presence of a significant pool of PTP1B there and a novel role for PTP1B in the regulation of mitochondrial ErbB1 activity. In summary, in addition to its well-established general localization along the ER, our results reveal that PTP1B specifically accumulates at MAM sites along the ER and localizes as well to the OMM and mitochondrial matrix. Further elucidation of PTP1B's roles in these different locations (including the identification of its targets) will likely be critical for understanding its complex regulation of general cellular responses, cell proliferation, and diseased states.

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Molecular cloning and chromosome mapping of the human gene encoding protein phosphotyrosyl phosphatase 1B.

Cited by 168 publications

References 45 publications

Expression, purification and crystallization of human phosphotyrosine phosphatase 1B

Expression, purification and crystallization of human phosphotyrosine phosphatase 1B

Attenuation of Adhesion-dependent Signaling and Cell Spreading in Transformed Fibroblasts Lacking Protein Tyrosine Phosphatase-1B

Journey to the Center of the Mitochondria Guided by the Tail Anchor of Protein Tyrosine Phosphatase 1B

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