The Ron oncogenic activity induced by the MEN2B-like substitution overcomes the requirement for the multifunctional docking site

Santoro, Massimo; Penengo, Lorenza; Orecchia, Sara; Cilli, Michele; Gaudino, Giovanni

doi:10.1038/sj.onc.1203819

Cited by 17 publications

(30 citation statements)

References 23 publications

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“…Thus, our kinetic experiments show that RON phosphorylates the EGFR peptide with a k cat /K m value Ͼ 17-fold higher than that seen with a preferred substrate for another RTK, insulin receptor kinase. Previous experiments with immunoprecipitated RON also showed that RON preferred the EGFR peptide sequence (29). In those studies, however, a Src substrate sequence was phosphorylated roughly equally to the EGFR sequence, whereas in our studies (Table I) we found a difference of ϳ24-fold in terms of k cat /K m .…”

Section: Purification Of Ron and Kinetics Of Peptide Phosphorylation-contrasting

confidence: 55%

The C Terminus of RON Tyrosine Kinase Plays an Autoinhibitory Role

Yokoyama

Ischenko

Hayman

et al. 2005

Journal of Biological Chemistry

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RON is a receptor tyrosine kinase in the MET family. We have expressed and purified active RON using the Sf9/baculovirus system. The constructs used in this study comprise the kinase domain alone and the kinase domain plus the C-terminal region. The construct containing the kinase domain alone has a higher specific activity than the construct containing the kinase and C-terminal domains. Purified RON undergoes autophosphorylation, and the exogenous RON C terminus serves as a substrate. Peptides containing a dityrosine motif derived from the C-terminal tail inhibit RON in vitro or when delivered into intact cells, consistent with an autoinhibitory mechanism. Phenylalanine substitutions within these peptides increase the inhibitory potency. Moreover, introduction of these Phe residues into the dityrosine motif of the RON kinase leads to a decrease in kinase activity. Taken together, our data suggest a model in which the C-terminal tail of RON regulates kinase activity via an interaction with the kinase catalytic domain.

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Section: Purification Of Ron and Kinetics Of Peptide Phosphorylation-contrasting

confidence: 55%

The C Terminus of RON Tyrosine Kinase Plays an Autoinhibitory Role

Yokoyama

Ischenko

Hayman

et al. 2005

Journal of Biological Chemistry

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“…Also Ron can harbor oncogenic mutations in a conserved region of the kinase domain (10). One of these substitutions (M1254T) shifts substrate specificity and overcomes the requirement for the multifunctional docking site (11).…”

Section: Discussionmentioning

confidence: 99%

“…This mutant harbors a point mutation responsible for constitutive activation of the kinase and for overcoming the requirement for the multifunctional docking site of the Ron receptor (10,11).…”

Section: Chip Is Responsible For Oncogenic Ronmentioning

confidence: 99%

“…Ron is expressed in a variety of human tissues, and the engagement by its cognate ligand activates multiple intracellular signaling pathways controlling normal cell proliferation, migration, and adhesion-dependent survival (7)(8)(9). A single point mutation (M1254T), targeted to a conserved residue of the tyrosine kinase domain is oncogenic (Ron M1254T ), by increasing kinase efficiency and subverting substrate specificity (10,11). Growing evidence indicates that Ron can be involved in cancer development and progression in humans (12,13) and in murine models (14,15).…”

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confidence: 99%

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Geldanamycins Trigger a Novel Ron Degradative Pathway, Hampering Oncogenic Signaling

Germano

Barberis

Santoro

et al. 2006

Journal of Biological Chemistry

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Ron, the tyrosine kinase receptor for macrophage-stimulating protein is responsible for proliferation and migration of cells from different tissues. Ron can acquire oncogenic potential by single point mutations in the kinase domain, and dysregulated Ron signaling has been involved in the development of different human cancers. We have previously shown that ligand-activated Ron recruits the negative regulator c-Cbl, which mediates its ubiquitylation and degradation. Here we report that Ron is ubiquitylated also by the U-box E3 ligase C-terminal Hsc70-interacting protein (CHIP), recruited via chaperone intermediates Hsp90 and Hsc70. Gene silencing shows that CHIP activity is necessary to mediate Ron degradation upon cell treatment with Hsp90 inhibitors geldanamycins. The oncogenic Ron M1254T receptor escapes from c-Cbl negative regulation but retains a strong association with CHIP. This constitutively active mutant of Ron displays increased sensitivity to geldanamycins, enhanced physical interaction with Hsp90, and more rapid degradation rate. Cell growth and migration, as well as the transforming potential evoked by Ron M1254T , are abrogated upon Hsp90 inhibition. These data highlight a novel mechanism for Ron degradation and propose Hsp90 antagonists like geldanamycins as suitable pharmacological agents for therapy of cancers where altered Ron signaling is involved. Dysregulated activation of receptor tyrosine kinases (RTKs)3 has been extensively documented in different types of human tumors (1) and frequently correlates with poor responsiveness to conventional therapies, pointing at RTKs as potential targets for molecule-based cancer therapy (2, 3). Among the different therapeutic approaches a promising strategy relies on forcing RTKs toward degradative pathways (4).The Ron tyrosine kinase, receptor for macrophage-stimulating protein (MSP), is a member of the hepatocyte growth factor (HGF) receptor subfamily (5, 6). Ron is expressed in a variety of human tissues, and the engagement by its cognate ligand activates multiple intracellular signaling pathways controlling normal cell proliferation, migration, and adhesion-dependent survival (7-9). A single point mutation (M1254T), targeted to a conserved residue of the tyrosine kinase domain is oncogenic (Ron M1254T ), by increasing kinase efficiency and subverting substrate specificity (10, 11). Growing evidence indicates that Ron can be involved in cancer development and progression in humans (12, 13) and in murine models (14, 15). Therefore, targeting Ron expression by forcing its down-regulation may help to elucidate its role in tumor development and progression.It has been reported that many kinases that are deregulated in human cancers are dependent on the chaperone activity of the Heat shock protein 90 (Hsp90) for their conformational maturation and stability (16). Hsp90 is a ubiquitous chaperone protein abundantly expressed in mammalian cells, where it performs housekeeping functions assisting in the folding, activation, and assembly of a variety of proteins...

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“…Similarly, the 2B mutation in HGF receptor MET (Met M1268T ) has been identified in metastatic renal carcinomas (10,24). Introduction of the 2B mutation in other RTKs, such as RON and epidermal growth factor receptor (EGFR), caused transformation of NIH 3T3 cells with high metastatic potential (20,23). Although the 2B mutation enhanced kinase activity and such a mutation has been suspected as a gain-of-function mutation (21,29,35), the role of the Thr pϩ1loop residue in RTK catalytic activity in recruiting specific substrate(s) responsible for the metastatic phenotype has not been clarified.…”

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confidence: 99%

Central Role of the Threonine Residue within the p+1 Loop of Receptor Tyrosine Kinase in STAT3 Constitutive Phosphorylation in Metastatic Cancer Cells

Yuan¹,

Guan²,

Wang³

et al. 2004

Molecular and Cellular Biology

132

109

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The receptor tyrosine kinases (RTKs) RET, MET, and RON all carry the Met p؉1loop 3Thr point mutation (i.e., 2B mutation), leading to the formation of tumors with high metastatic potential. Utilizing a novel antibody array, we identified constitutive phosphorylation of STAT3 in cells expressing the 2B mutation but not wild-type RET. MET or RON with the 2B mutation also constitutively phosphorylated STAT3. Members of the EPH, the only group of wild-type RTK that carry Thr p؉1loop residue, are often expressed unexpectedly in different types of cancers. Ectopic expression of wild-type but not Thr p؉1loop 3Met substituted EPH family members constitutively phosphorylated STAT3. In both RTK Metp؉1loop with 2B mutation and wild-type EPH members the Thr p؉1loop residue is required for constitutive kinase autophosphorylation and STAT3 recruitment. In multiple endocrine neoplasia 2B (MEN-2B) patients expressing RET M918T , nuclear enrichment of STAT3 and elevated expression of CXCR4 was detected in metastatic thyroid C-cell carcinoma in the liver. In breast adenocarcinoma cell lines expressing multiple EPH members, STAT3 constitutively bound to the promoters of MUC1, MUC4, and MUC5B genes. Inhibiting STAT3 expression resulted in reduced expression of these metastasis-related genes and inhibited mobility. These findings provide insight into Thr p؉1loop residue in RTK autophosphorylation and constitutive activation of STAT3 in metastatic cancer cells.Growth factor receptors are transmembrane protein tyrosine kinases playing critical roles in biological processes, including proliferation, survival, and migration. The core region of the kinase domain, comprising the catalytic loop, the activation loop, and the pϩ1 loop, is well conserved in receptor tyrosine kinases (RTKs) of different species. RTKs with different types of mutations within these three loops have been associated with developmental disorders and cancer. The point mutation (ATG3ACG), resulting in replacement of methionine with threonine within the pϩ1 loop, is associated with aggressive tumors. RET is an RTK that can activate a variety of signaling pathways, including the RAS/ERK, PI3K/AKT, and phospholipase C␥ pathways and plays an important role in neuron survival or differentiation (11). RET with a Met pϩ1loop 3Thr substitution (RET M918T ) is associated with the multiple endocrine neoplasia 2B type (MEN-2B) syndrome; this substitution is defined as the 2B mutation (11). In MEN-2B patients, the tumors derived from thyroid C cells are often more aggressive than C-cell tumors that develop in MEN-2A patients who carry mutations in the extracellular domain of RET (11,22). Similarly, the 2B mutation in HGF receptor MET (Met M1268T ) has been identified in metastatic renal carcinomas (10,24). Introduction of the 2B mutation in other RTKs, such as RON and epidermal growth factor receptor (EGFR), caused transformation of NIH 3T3 cells with high metastatic potential (20,23). Although the 2B mutation enhanced kinase activity and such a mutation has been suspected as a g...

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The Ron oncogenic activity induced by the MEN2B-like substitution overcomes the requirement for the multifunctional docking site

Cited by 17 publications

References 23 publications

The C Terminus of RON Tyrosine Kinase Plays an Autoinhibitory Role

The C Terminus of RON Tyrosine Kinase Plays an Autoinhibitory Role

Geldanamycins Trigger a Novel Ron Degradative Pathway, Hampering Oncogenic Signaling

Central Role of the Threonine Residue within the p+1 Loop of Receptor Tyrosine Kinase in STAT3 Constitutive Phosphorylation in Metastatic Cancer Cells

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