Expression of MAT1/PEA-15 mRNA isoforms during physiological and neoplastic changes in the mouse mammary gland

Tsukamoto, Tetsuya; Yoo, Jakyoung; Hwang, Soo In; Guzman, Raphaël; Hirokawa, Yoshifumi; Chou, Yu Chien; Olatunde, Sumaiya; Huang, Tony T.; Bera, Tapan K.; Yang, Jason; Nandi, Satyabrata

doi:10.1016/s0304-3835(99)00350-x

Cited by 22 publications

(25 citation statements)

References 32 publications

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“…Various cancer cell lines also express relatively high amounts of PEA-15, and an increase in its mRNA is correlated with neoplastic changes in mouse mammary gland (26). Consistent with its anti-apoptotic phenotypes, PEA-15 contains a death effector domain, which is required for PEA-15 to reverse Ras-mediated suppression of integrin activation (27).…”

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confidence: 74%

The Death Effector Domain Protein PEA-15 Prevents Nuclear Entry of ERK2 by Inhibiting Required Interactions

Whitehurst

Robinson

Moore

et al. 2004

Journal of Biological Chemistry

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ERK2 nuclear-cytoplasmic distribution is regulated in response to hormones and cellular state without the requirement for karyopherin-mediated nuclear import. One proposed mechanism for the movement of ERK2 into the nucleus is through a direct interaction between ERK2 and nucleoporins present in the nuclear pore complex. Previous reports have attributed regulation of ERK2 localization to proteins that activate or deactivate ERK2, such as the mitogen-activated protein (MAP) kinase kinase MEK1 and MAP kinase phosphatases. Recently, a small non-catalytic protein, PEA-15, has also been demonstrated to promote a cytoplasmic ERK2 localization. We found that the MAP kinase insert in ERK2 is required for its interaction with PEA-15. Consistent with its recognition of the MAP kinase insert, PEA-15 blocked activation of ERK2 by MEK1, which also requires the MAP kinase insert to interact productively with ERK2. To determine how PEA-15 influences the localization of ERK2, we used a permeabilized cell system to examine the effect of PEA-15 on the localization of ERK2 and mutants that have lost the ability to bind PEA-15. Wild type ERK2 was unable to enter the nucleus in the presence of an excess of PEA-15; however, ERK2 lacking the MAP kinase insert largely retained the ability to enter the nucleus. Binding assays demonstrated that PEA-15 interfered with the ability of ERK2 to bind to nucleoporins. These results suggest that PEA-15 sequesters ERK2 in the cytoplasm at least in part by interfering with its ability to interact with nucleoporins, presenting a potential paradigm for regulation of ERK2 localization.The mitogen-activated protein (MAP) 1 kinase, ERK2, plays a critical role in promoting cellular changes in response to both mitogenic and non-mitogenic stimuli. ERK2 is the multifunctional kinase in a kinase cascade that is activated by various stimuli acting through tyrosine kinase receptors, G proteincoupled receptors, and others (1, 2). Activation of this cascade results in the dual phosphorylation of ERK2 and the consequent phosphorylation of target kinases, transcription factors, and other proteins throughout the cell. The effectors of ERK2 are localized in both the cytoplasm and the nucleus, making its subcellular localization important for its ability to induce cellular changes (3, 4).Regulation of ERK2 localization has been characterized mostly by overexpression and/or by using antibodies to N-and C-terminal epitopes (5, 6); these epitopes are not readily accessible in ERK2 that is associated with microtubules, which constitutes a large portion of the cytoplasmic protein (7). ERK2 and its upstream activator the MAP/ERK kinase MEK1 (also known as MKK1) interact stably through multiple sites with an affinity in the micromolar range (8 -14). Overexpressed ERK2 accumulates in the nucleus in a stimulus-independent manner. This suggests that cytosolic binding is important in determining the distribution of ERK2 in cells. Coexpression with MEK1 shifts the distribution in favor of the cytoplasm (13). From these studies,...

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confidence: 74%

The Death Effector Domain Protein PEA-15 Prevents Nuclear Entry of ERK2 by Inhibiting Required Interactions

Whitehurst

Robinson

Moore

et al. 2004

Journal of Biological Chemistry

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“…Indeed, ped/pea-15 is highly expressed in human glioma and metastatic breast cancer cell lines and induces resistance to chemotherapic agents in these cells (Ramos et al, 2000;Hao et al, 2001;Condorelli et al, 2002;Trencia et al, 2004). ped/pea-15 is also expressed at high levels in tumor cell lines derived from human larynx, cervix, and skin tumors (Condorelli et al, 1998), and in human mammary carcinomas as well (Tsukamoto et al, 2000). Finally, the ped/pea-15 gene was demonstrated to be increasingly expressed during tumor progression in murine squamous carcinomas (Dong et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Raised expression of the antiapoptotic protein ped/pea-15 increases susceptibility to chemically induced skin tumor development

et al. 2005

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ped/pea-15 is a cytosolic protein performing a broad antiapoptotic function. We show that, upon DMBA/TPAinduced skin carcinogenesis, transgenic mice overexpressing ped/pea-15 (Tg ped/pea-15 ) display early development of papillomas and a four-fold increase in papilloma number compared to the nontransgenic littermates (Po0.001). The malignant conversion frequency was 24% for the Tg ped/pea-15 mice and only 5% in controls (Po0.01). The isolated application of TPA, but not that of DMBA, was sufficient to reversibly upregulate ped/pea-15 in both untransformed skin and cultured keratinocytes. ped/pea-15 protein levels were also increased in DMBA/TPAinduced papillomas of both Tg ped/pea-15 and control mice. Isolated TPA applications induced Caspase-3 activation and apoptosis in nontransformed mouse epidermal tissues. The induction of both Caspase-3 and apoptosis by TPA were four-fold inhibited in the skin of the Tg ped/pea-15 compared to the nontransgenic mice, accompanied by a similarly sized reduction in TPA-induced JNK and p38 stimulation and by constitutive induction of cytoplasmic ERK activity in the transgenics. ped/pea-15 expression was stably increased in cell lines from DMBA/TPAinduced skin papillomas and carcinomas, paralleled by protection from TPA apoptosis. In the A5 spindle carcinoma cell line, antisense inhibition of ped/pea-15 expression simultaneously rescued sensitivity to TPAinduced Caspase-3 function and apoptosis. The antisense also reduced A5 cell ability to grow in semisolid media by 65% (Po0.001) and increased by three-fold tumor latency time (Po0.01). Thus, the expression levels of ped/pea-15 control Caspase-3 function and epidermal cell apoptosis in vivo and determine susceptibility to skin tumor development.

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“…Controlling the localization of ERK2 is a mechanism by which cell function may be influenced. For example, PEA15, which promotes the cytoplasmic retention of ERK2, is overexpressed in disease states, such as type II diabetes and breast cancer (3,4). ERK2 is active and constitutively nuclear in certain breast cancer cells, but excluded from the nucleus in certain nonsmall cell lung cancers (ref.…”

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confidence: 99%

ERK2 enters the nucleus by a carrier-independent mechanism

Whitehurst

Wilsbacher

You

et al. 2002

Proc. Natl. Acad. Sci. U.S.A.

141

125

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In stimulated cells, the mitogen-activated protein kinase ERK2 (extracellular signal-regulated kinase 2) concentrates in the nucleus. Evidence exists for CRM1-dependent, mitogen-activated protein kinase kinase-mediated nuclear export of ERK2, but its mechanism of nuclear entry is not understood. To determine requirements for nuclear transport, we tagged ERK2 with green fluorescent protein (GFP) and examined its nuclear uptake by using an in vitro import assay. GFP-ERK2 entered the nucleus in a saturable, time-and temperature-dependent manner. Entry of GFP-ERK2, like that of ERK2, required neither energy nor transport factors and was visible within minutes. The nuclear uptake of GFP-ERK2 was inhibited by wheat germ agglutinin, which blocks nuclear entry by binding to carbohydrate moieties on nuclear pore complex proteins. The nuclear uptake of GFP-ERK2 also was reduced by excess amounts of recombinant transport factors. These findings suggest that ERK2 competes with transport factors for binding to nucleoporins, which mediate the entry and exit of transport factors. In support of this hypothesis, we showed that ERK2 binds directly to a purified nucleoporin. Our data suggest that GFP-ERK2 enters the nucleus by a saturable, facilitated mechanism, distinct from a carrier-and energy-dependent import mechanism and involves a direct interaction with nuclear pore complex proteins.mitogen-activated protein kinase ͉ import ͉ FXFG motif ͉ nucleoporins M itogen-activated protein (MAP) kinases are ubiquitous protein kinases that integrate cell surface signals by phosphorylating proteins throughout the cell. The MAP kinase ERK2 (extracellular signal-regulated kinase 2) targets proteins in multiple cell compartments after an activating stimulus. Stimuli induce the nuclear accumulation of ERK2 from its resting location in the cytoplasm of many types of cells, including fibroblasts, epithelial cells, and neuroendocrine cells (1, 2).The location of ERK2 is a significant factor in determining its ability to phosphorylate key substrates and thereby influence cell behavior. Controlling the localization of ERK2 is a mechanism by which cell function may be influenced. For example, PEA15, which promotes the cytoplasmic retention of ERK2, is overexpressed in disease states, such as type II diabetes and breast cancer (3, 4). ERK2 is active and constitutively nuclear in certain breast cancer cells, but excluded from the nucleus in certain nonsmall cell lung cancers (ref. 5, S. Muneer, personal communication). In addition to extensive data suggesting a correlation between phenotypes and ERK2 localization, some cell behaviors have been demonstrated to occur only if ERK2 accumulates in the nucleus. For example, the nuclear localization of ERK2 is essential for morphological transformation of 3T3 fibroblasts and neurite extension in PC12 cells (6, 7). An understanding of how ERK2 localization is regulated will provide important insights into its normal function and disease mechanisms.ERK2 subcellular localization is mediated by interactions w...

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Expression of MAT1/PEA-15 mRNA isoforms during physiological and neoplastic changes in the mouse mammary gland

Cited by 22 publications

References 32 publications

The Death Effector Domain Protein PEA-15 Prevents Nuclear Entry of ERK2 by Inhibiting Required Interactions

The Death Effector Domain Protein PEA-15 Prevents Nuclear Entry of ERK2 by Inhibiting Required Interactions

Raised expression of the antiapoptotic protein ped/pea-15 increases susceptibility to chemically induced skin tumor development

ERK2 enters the nucleus by a carrier-independent mechanism

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