Identification of novel nuclear localization signal within the ErbB-2 protein

Chen, Qiao Qiao; Chen, Xiao Ying; Jiang, Yun; Liu, Jing

doi:10.1038/sj.cr.7290320

Cited by 37 publications

(30 citation statements)

References 28 publications

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“…We conclude that emerin is a target of Her2-mediated signaling in vivo. Her2, a plasma membrane protein, might also localize in the nucleus (Chen et al, 2005;Wang et al, 2004). However, Her2 more conventionally acts indirectly, by activating downstream effector tyrosine kinases (Yarden and Sliwkowski, 2001).…”

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confidence: 99%

Tyrosine phosphorylation of nuclear-membrane protein emerin by Src, Abl and other kinases

Tifft

Bradbury

Wilson

2009

Journal of Cell Science

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X-linked recessive Emery-Dreifuss muscular dystrophy (EDMD) is caused by loss of emerin, a nuclear-membrane protein with roles in nuclear architecture, gene regulation and signaling. Phosphoproteomic studies have identified 13 sites of tyrosine phosphorylation in emerin. We validated one study, confirming that emerin is hyper-tyrosine-phosphorylated in Her2-overexpressing cells. We discovered that non-receptor tyrosine kinases Src and Abl each phosphorylate emerin and a related protein, LAP2, directly. Src phosphorylated emerin specifically at Y59, Y74 and Y95; the corresponding triple Yto-F ('FFF') mutation reduced tyrosine phosphorylation bỹ 70% in vitro and in vivo. Substitutions that removed a single hydroxyl moiety either decreased (Y19F, Y34, Y161F) or increased (Y4F) emerin binding to BAF in cells. Y19F, Y34F, Y161F and the FFF mutant also reduced recombinant emerin binding to BAF from HeLa lysates, demonstrating the involvement of both LEM-domain and distal phosphorylatable tyrosines in binding BAF. We conclude that emerin function is regulated by multiple tyrosine kinases, including Her2, Src and Abl, two of which (Her2, Src) regulate striated muscle. These findings suggest roles for emerin as a downstream effector and 'signal integrator' for tyrosine kinase signaling pathway(s) at the nuclear envelope.Key words: Emerin, LEM domain, Nuclear envelope, Emery-Dreifuss muscular dystrophy, Src, Her2, Abl, Barrier-to-autointegration factor (BAF), Cardiomyopathy, Breast cancer, Laminopathy, Neuromuscular junction Journal of Cell Science 3781 Emerin tyrosine phosphorylation receptor tyrosine kinases that can be activated by Her2 or other signaling pathways (Roskoski, 2005;Srinivasan and Plattner, 2006). We confirm Her2-stimulated emerin tyrosine phosphorylation and report that emerin and LAP2 are phosphorylated directly by Src and Abl. We also show that tyrosine phosphorylation of emerin regulates binding to BAF. ResultsWe compiled data from 13 independent proteomic studies (Amanchy et al., 2005;Brill et al., 2004;Cantin et al., 2008; Daub et al., 2008; Guo et al., 2008;Olsen et al., 2006;Pan et al., 2008;Rikova et al., 2007;Rush et al., 2005;Schlosser et al., 2006;Sui et al., 2008;Tao et al., 2005;Tsai et al., 2008), which identified 13 phosphorylated tyrosines in emerin (Fig. 1A). All sites except Y19 and Y41 were identified more than once. All 13 identified phosphorylated Tyr (Tyr-P) residues in human emerin are conserved in mouse, and six (corresponding to Y4, Y41, Y94, Y95, Y105, Y161) are conserved in Xenopus (Fig. 1B). These studies did not reveal responsible pathways or kinases.We validated tyrosine phosphorylation of emerin by immunoprecipitating endogenous emerin from HeLa cells treated with 1 M pervanadate (PV, a tyrosine phosphatase inhibitor) (Huyer et al., 1997) or buffer (PBS) as control, for 30 minutes before lysing cells. Emerin immunoprecipitated from PV-treated cells was specifically recognized by Tyr-P antibodies (not shown; see Fig. 2B). No other tyrosine-phosphorylated bands were dete...

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confidence: 99%

Tyrosine phosphorylation of nuclear-membrane protein emerin by Src, Abl and other kinases

Tifft

Bradbury

Wilson

2009

Journal of Cell Science

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“…In addition to this classic RTK signaling model, ErbB RTKs have exhibited nuclear localization (4,17,19,27,28,37,47,48). While ErbB1, -2, and -3 are transported to the nucleus as full-length receptors, one isoform of ErbB4 is cleaved upon ligand binding, liberating the entire soluble intracellular domain.…”

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confidence: 99%

ErbB4 Splice Variants Cyt1 and Cyt2 Differ by 16 Amino Acids and Exert Opposing Effects on the Mammary Epithelium In Vivo

Muraoka-Cook¹,

Sandahl²,

Strunk³

et al. 2009

Molecular and Cellular Biology

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Data concerning the prognostic value of ErbB4 in breast cancer and effects on cell growth have varied in published reports, perhaps due to the unknown signaling consequences of expression of the intracellular proteolytic ErbB4 s80 HER4 fragment or due to differing signaling capabilities of alternatively spliced ErbB4 isoforms. One isoform (Cyt1) contains a 16-residue intracellular sequence that is absent from the other (Cyt2). We expressed s80Cyt1 and s80 Cyt2 in HC11 mammary epithelial cells, finding diametrically opposed effects on the growth and organization of colonies in three-dimensional matrices. Whereas expression of s80Cyt1 decreased growth and increased the rate of three-dimensional lumen formation, that of s80Cyt2 increased proliferation without promoting lumen formation. These results were recapitulated in vivo, using doxycyclineinducible, mouse breast-transgenic expression of s80 Cyt1 amd s80 Cyt2 . Expression of s80 Cyt1 decreased growth of the mammary ductal epithelium, caused precocious STAT5a activation and lactogenic differentiation, and increased cell surface E-cadherin levels. Remarkably, ductal growth inhibition by s80Cyt1 occurred simultaneously with lobuloalveolar growth that was unimpeded by s80Cyt1 , suggesting that the response to ErbB4 may be influenced by the epithelial subtype. In contrast, expression of s80 Cyt2 caused epithelial hyperplasia, increased Wnt and nuclear ␤-catenin expression, and elevated expression of c-myc and cyclin D1 in the mammary epithelium. These results demonstrate that the Cyt1 and Cyt2 ErbB4 isoforms, differing by only 16 amino acids, exhibit markedly opposing effects on mammary epithelium growth and differentiation.Activation of the ErbB/HER/epidermal growth factor receptor (ErbB/HER/EGFR) family of receptor tyrosine kinases (RTKs) is often equated with proliferation and oncogenesis. The family consists of four members, HER1/ErbB1/EGFR, HER2/ErbB2/Neu, HER3/ErbB3, and HER4/ErbB4. Each protein has a large NH 2 -terminal extracellular domain, a transmembrane domain, and a large intracellular domain with a tyrosine-rich carboxy-terminal region and a tyrosine kinaselike sequence (12). HER1/ErbB1, HER2/ErbB2, and HER4/ ErbB4 exhibit ligand-inducible tyrosine kinase activity, whereas HER3/ErbB3 does not.ErbB receptor activation at the cell surface targets multiple cytoplasmic signaling cascades that transmit signals to the nucleus. In addition to this classic RTK signaling model, ErbB RTKs have exhibited nuclear localization (4,17,19,27,28,37,47,48). While ErbB1, -2, and -3 are transported to the nucleus as full-length receptors, one isoform of ErbB4 is cleaved upon ligand binding, liberating the entire soluble intracellular domain. This intracellular, kinase-active 80-kDa cleavage product (s80 HER4 ) exhibits nuclear-cytoplasmic shuttling (8,20,25,27 (14,21,44). Inhibition of ErbB4 cleavage or its nuclear localization impairs ErbB4-mediated STAT5a activation (25,46,48).Evidence suggests that, whereas ErbB1, -2, and -3 all contribute to proliferation and/or survi...

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“…A nuclear localization sequence (NLS) was identified in all ErbBs (Offterdinger et al 2002, Wang et al 2004, Williams et al 2004, Lo et al 2005. The NLS is located adjacent to the transmembrane domain in ErbB-2 and contains three clusters of basic amino acids (676-KRRQQKIRKYTMRR-689) (Chen et al 2005, Giri et al 2005, Hsu & Hung 2007 (Fig. 1).…”

Section: :12mentioning

confidence: 99%

ErbB-2 nuclear function in breast cancer growth, metastasis and resistance to therapy

Elizalde¹,

Russo²,

Chervo³

et al. 2016

Endocrine-Related Cancer

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Approximately 15-20% of breast cancers (BC) show either membrane overexpression of ErbB-2 (MErbB-2), a member of the ErbBs family of receptor tyrosine kinases, or ERBB2 gene amplification. Until the development of MErbB-2-targeted therapies, this BC subtype, called ErbB-2-positive, was associated with increased metastatic potential and poor prognosis. Although these therapies have significantly improved overall survival and cure rates, resistance to available drugs is still a major clinical issue. In its classical mechanism, MErbB-2 activates downstream signaling cascades, which transduce its effects in BC. The fact that ErbB-2 is also present in the nucleus of BC cells was discovered over twenty years ago. Also, compelling evidence revealed a non-canonical function of nuclear ErbB-2 as a transcriptional regulator. As a deeper understanding of nuclear ErbB-2 actions would be crucial to the disclosure of its role as a biomarker and a target of therapy in BC, we will here review its function in BC, in particular, its role in growth, metastatic spreading and response to currently available MErbB-2-positive BC therapies.

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Identification of novel nuclear localization signal within the ErbB-2 protein

Cited by 37 publications

References 28 publications

Tyrosine phosphorylation of nuclear-membrane protein emerin by Src, Abl and other kinases

Tyrosine phosphorylation of nuclear-membrane protein emerin by Src, Abl and other kinases

ErbB4 Splice Variants Cyt1 and Cyt2 Differ by 16 Amino Acids and Exert Opposing Effects on the Mammary Epithelium In Vivo

ErbB-2 nuclear function in breast cancer growth, metastasis and resistance to therapy

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