Protein Tyrosine Phosphatases: Emerging Regulators of Apoptosis

Hallé, Maxime; Tremblay, Michel L.; Meng, Tzu‐Ching

doi:10.4161/cc.6.22.4926

Cited by 34 publications

(22 citation statements)

References 95 publications

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“…Moreover, apoptosis was associated with the activation of caspase-3, -8 and -9, and an increasing Bax:Bcl-2 ratio, followed by release of cytochrome c (17). Caspase-3 is a key molecule in the late stage of apoptosis; caspase-8 normally is activated by extrinsic receptor-mediated pathway; and caspase-9 is activated by intrinsic mitochondrial-mediated pathway (18).…”

Section: Discussionmentioning

confidence: 99%

Receptor-like protein tyrosine phosphatase κ negatively regulates the apoptosis of prostate cancer cells via the JNK pathway

Park

Mason

et al. 2013

International Journal of Oncology

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Abstract. Receptor-like protein tyrosine phosphatase κ (PTPRK) has been indicated as a putative tumour suppressor in primary central nervous system lymphomas and colorectal cancer. The present study investigated the expression of PTPRK in prostate cancer and the biological impact of PTPRK on prostate cancer cells. The expression of the PTPRK protein and transcript in prostate cancer was examined using IHC and PCR. Knockdown of PTPRK in prostate cancer cells was performed using a specific anti-PTPRK transgene. The impact of PTPRK knockdown on prostate cancer cells was evaluated using in vitro cell models and the apoptosis was analysed using flow cytometry. PTPRK expression was increased in prostate cancer tissues and knockdown of PTPRK in PC-3 cells suppressed the in vitro cell growth in which an increased apoptotic population was seen. Accompanied with the knockdown of PTPRK, increased expression of caspase-3, caspase-8 and p53, and a decreased ID1 expression were evident in the cells. Furthermore, an increased tyrosine phosphorylated c-Jun N-terminal kinase (JNK) was seen in the PTPRK knockdown cells. The effect on apoptosis was diminished by a JNK inhibitor. In conclusion, PTPRK knockdown resulted in increased apoptosis leading to the inhibition of in vitro growth of prostate cancer cells. PTPRK is a key factor in coordinating apoptosis via the regulation of MAPK pathways, in particular the JNK pathway in prostate cancer cells.

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Section: Discussionmentioning

confidence: 99%

Receptor-like protein tyrosine phosphatase κ negatively regulates the apoptosis of prostate cancer cells via the JNK pathway

Park

Mason

et al. 2013

International Journal of Oncology

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“…The assembly of the PTP-PEST-PSTPIP-WASP complexes was previously shown to allow PTP-PEST to dephosphorylate WASP (19) and to inhibit WASP-induced actin polymerization (82). It was recently demonstrated that caspase-3-mediated cleavage of PTP-PEST dissociates its phosphatase domain from PSTPIP and was expected to prevent it from dephosphorylating and inhibiting WASP (51,83). Importantly, we show that GP63 mediates the degradation of PTP-PEST during Leishmania infection, which could function to affect parasite-induced actin cytoskeleton remodeling.…”

Section: Discussionmentioning

confidence: 99%

The Leishmania Surface Protease GP63 Cleaves Multiple Intracellular Proteins and Actively Participates in p38 Mitogen-activated Protein Kinase Inactivation

Hallé

Gómez

Stuible

et al. 2009

Journal of Biological Chemistry

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127

107

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The Leishmania parasite is a widespread disease threat in tropical areas, causing symptoms ranging from skin lesions to death. Leishmania parasites typically invade macrophages but are also capable of infecting fibroblasts, which may serve as a reservoir for recurrent infection. Invasion by intracellular pathogens often involves exploitation of the host cell cytoskeletal and signaling machinery. Here we have observed a dramatic rearrangement of the actin cytoskeleton and marked modifications in the profile of protein tyrosine phosphorylation in fibroblasts infected with Leishmania major. Correspondingly, exposure to L. major resulted in degradation of the phosphorylated adaptor protein p130Cas and the protein-tyrosine phosphatase-PEST. Cellular and in vitro assays using pharmacological protease inhibitors, recombinant enzyme, and genetically modified strains of L. major identified the parasite protease GP63 as the principal catalyst of proteolysis during infection. A number of additional signaling proteins were screened for degradation during L. major infection as follows: a small subset was cleaved, including cortactin, T-cell protein-tyrosine phosphatase, and caspase-3, but the majority remained unaffected. Protein degradation occurred in cells incubated with Leishmania extracts in the absence of intact parasites, suggesting a mechanism permitting transfer of functional GP63 into the intracellular space. Finally, we evaluated the impact of Leishmania on MAPK signaling; unlike p44/42 and JNK, p38 was inactivated upon infection in a GP63-and protein degradation-dependent manner, which likely involves cleavage of the upstream adaptor TAB1. Our results establish that GP63playsacentralroleinanumberofhostcellmoleculareventsthat likely contribute to the infectivity of Leishmania.

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“…PTP1B was originally isolated from human placenta (Charbonneau et al 1989) and is well known to play a major role in the regulation of the immune system, insulin signaling, and cell cycle, as well as in metabolic diseases and various cancers (Tonks 2003;Dubé and Tremblay 2005;Ostman et al 2006). There is also a growing body of evidence that protein tyrosine phosphatases serve as signaling partners for apoptosis (Hallé et al 2007). The human Ptpip51 gene is located on chromosome 15 (15q15.1) and encodes the corresponding full-length protein making up 470 amino acids by 12 exons.…”

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confidence: 99%

Protein Tyrosine Phosphatase Interacting Protein 51 (PTPIP51) mRNA Expression and Localization and Its In Vitro Interacting Partner Protein Tyrosine Phosphatase 1B (PTP1B) in Human Placenta of the First, Second, and Third Trimester

Märker

Koch

Hoffmann

et al. 2008

J Histochem Cytochem.

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S U M M A R Y The cellular localization of protein tyrosine phosphatase 51 (PTPIP51) and its in vitro interacting partner protein tyrosine phosphatase 1B (PTP1B) was studied in human placentae of different gestational stages. The expression of PTPIP51 protein and mRNA was observed in the syncytiotrophoblast and cytotrophoblast layer of placentae from the first, second, and third trimesters. In contrast, PTP1B expression was restricted to the syncytiotrophoblast during all gestational stages. Cells of the cytotrophoblasts and parts of the syncytiotrophoblasts expressing high amounts of PTPIP51 were found to execute apoptosis as shown by TdT-mediated dUTP-biotin nick end labeling assay, cytokeratin 18f, and caspase 3 expression. PTPIP51 could also be traced in the endothelium and smooth muscle cells of placental arterial and venous vessels, identified by double immunostainings with antibodies directed against van Willebrand factor and a-smooth muscle actin. Some of these cells showing a high PTPIP51 reactivity were Ki67 positive, indicating proliferation. Additionally, a small population of placental CD14-positive macrophages and mesenchymal cells within the villous stroma were detected as PTPIP51 positive. Our data suggest that both proteins, PTPIP51 and PTP1B, play a role in differentiation and apoptosis of the cytotrophoblast and syncytiotrophoblast, respectively. Moreover, PTPIP51 may also serve as a cellular signaling partner in angiogenesis and vascular remodeling. (J Histochem Cytochem 57:143-153, 2009)

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Protein Tyrosine Phosphatases: Emerging Regulators of Apoptosis

Cited by 34 publications

References 95 publications

Receptor-like protein tyrosine phosphatase κ negatively regulates the apoptosis of prostate cancer cells via the JNK pathway

Receptor-like protein tyrosine phosphatase κ negatively regulates the apoptosis of prostate cancer cells via the JNK pathway

The Leishmania Surface Protease GP63 Cleaves Multiple Intracellular Proteins and Actively Participates in p38 Mitogen-activated Protein Kinase Inactivation

Protein Tyrosine Phosphatase Interacting Protein 51 (PTPIP51) mRNA Expression and Localization and Its In Vitro Interacting Partner Protein Tyrosine Phosphatase 1B (PTP1B) in Human Placenta of the First, Second, and Third Trimester

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