tpr-met oncogene product induces maturation-producing factor activation in Xenopus oocytes.

Daar, Ira; White, G A; Schuh, S M; Ferris, D K; Woude, George F. Vande

doi:10.1128/mcb.11.12.5985

Cited by 15 publications

(12 citation statements)

References 35 publications

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“…3A), as previously reported (34,35). In contrast, the kinase activity of Raf-1R89L factor receptor tyrosine kinase) in oocytes has been shown to induce GVBD, histone H1 kinase activity (an indicator of p34wc2 kinase activity), and MAPK activity (39,40). As we previously reported (18), GVBD and H1 kinase activity mediated by Tpr-Met or Ha-Rasvu2 was blocked in oocytes expressing KD Raf-i, but not in oocytes expressing WT Raf-1 (Fig.…”

Section: Identification Of Arg" As a Residue Of Raf-1 Required Formentioning

confidence: 74%

A single amino acid change in Raf-1 inhibits Ras binding and alters Raf-1 function.

Fabian

Vojtek

Cooper

et al. 1994

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

176

130

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Ras and Raf-1 are key proteins involved in the transmission of developmental and proliferative signals generated by receptor and nonreceptor tyrosine kinases. Genetic and biochemical studies demonstrate that Raf-1 functions downstrem of Ras in many sialig pathways. Although directly associates with GTP-bound Ras, an effect of this interaction on Raf-1 activity in vivo has not been established. To examine the biological consequence of the Ras/Raf-1 interaction in vivo, we set out to identify key residues of Raf-1 required for Ras binding. In this report, we show that a single amino acid mutation in Raf-1 (Arg8 to Leu) disrupted the interaction with Ras in vitro and in the yeast two-hybrid system. This mutation prevented Ras-mediated but not tyrosine kinase-mediated enzymatic activation of Raf-1 in the baculovirus/5f9 expression system. Furthermore, kinase-defective Raf-1 proteins containing the Arg'" -) Leu mutation were no longer dominantinhibitory or capable of blocking Ras-mediated signal transduction in Xenopus laevis oocytes. These results demonstrate that the association of Raf-1 and Ras modulates both the kinase activity and the biological function of Raf-1 and identify Arg8' as a critical residue involved in this interaction. In addition, the fng that tyrosine kinases can stimulate the enzymatic activity of Raf-1 proteins containing a mutation at the Rasinteraction site suggests that Raf-i can be activated by Rasindependent pathways. The Raf-1 and Ras protooncogene products serve as central intermediates in many signaling pathways by connecting upstream tyrosine kinases with downstream serine/threonine kinases, such as mitogen-activated protein kinase (MAPK) and MAPK kinase (MKK, also known as MEK) (1, 2). Ras is a membrane-localized guanine nucleotide-binding protein that is biologically active in the GTP-bound state (3, 4). Raf-1 is a protein-serine/threonine kinase located primarily in the cytosol (5, 6). Growth factors that stimulate cellular proteintyrosine kinase activity enhance both the kinase activity of Raf-1 and the proportion ofRas bound to GTP (reviewed in ref. 7). The activation of Raf-1 in many cases is dependent on the activity ofRas, suggesting that Raf-1 functions downstream of . Further evidence positioning Raf-1 downstream of Ras comes from studies using deregulated and dominantinhibitory mutants ofRas and Raf-1 in mammalian cells (9-15), as well as from studies examining developmental pathways in Drosophila melanogaster, Xenopus laevis, and Caenorhabditis elegans (16)(17)(18)(19). Recently, Raf-1 has been shown to interact directly with GTP-bound forms of Ras in vitro and in yeast two-hybrid expression systems (20-25). Ras has also been reported to coimmunoprecipitate with Raf-1 from stimulated, but not unstimulated, mammalian cells (26,27). On the basis of these experiments and genetic and biochemical studies positioning Raf-1 downstream ofRas, Raf-1 has been proposed to be a direct effector ofRas. However, whether Raf-1 activity is modulated by the association with Ras ha...

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Section: Identification Of Arg" As a Residue Of Raf-1 Required Formentioning

confidence: 74%

A single amino acid change in Raf-1 inhibits Ras binding and alters Raf-1 function.

Fabian

Vojtek

Cooper

et al. 1994

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

176

130

View full text Add to dashboard Cite

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“…SESE-MAPKK was moderately active as compared to wild-type MAPKK. 2 To produce a more active mutant of MAPKK, a deletion (32)(33)(34)(35)(36)(37)(38)(39)(40)(41)(42)(43)(44)(45)(46)(47)(48)(49)(50)(51) near the N-terminal was introduced into Xenopus SESE-MAPKK according to the method of Mansour et al (43) using primers (5Ј-AGCCTCGAGGTTTGTCTCGGCTGTAGGG-3Ј and 5Ј-CGTCTCGAGGCTTTTCTCACCCAGAAGC-3Ј) and was ligated at the XhoI site, yielding dSESE-MAPKK. This Xenopus dSESE-MAPKK can function as a strongly active mutant in Xenopus oocytes (this study) and in COS cells.…”

Section: Methodsmentioning

confidence: 99%

Initiation of Xenopus Oocyte Maturation by Activation of the Mitogen-activated Protein Kinase Cascade

Gotoh

Masuyama

Dell

et al. 1995

Journal of Biological Chemistry

162

140

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“…For example, germinal vesicle breakdown (GVBD) is induced by receptors for insulin-like growth factor (42,50), epidermal growth factor (51), nerve growth factor (52), and activated forms of hepatocyte growth factor (Tpr-Met) (53) and the glial cell-derived neurotrophic factor (Ret) (54). Although signal transduction by progesterone and RTKs results in the synthesis of Mos and the induction of MPF, the two pathways differ in several aspects.…”

mentioning

confidence: 99%

“…Although signal transduction by progesterone and RTKs results in the synthesis of Mos and the induction of MPF, the two pathways differ in several aspects. Although maturation induced by Tpr-Met and IGF-1 requires the stimulation of a phosphodiesterase, maturation induced by progesterone does not (42,53,(55)(56)(57)(58)(59). Furthermore, maturation-signaling cascades induced by IGF-1, but not those induced by progesterone, require the specific involvement of p21ras, GAP, and protein kinase C (60 -62).…”

mentioning

confidence: 99%

SNT1/FRS2 Mediates Germinal Vesicle Breakdown Induced by an Activated FGF Receptor1 in Xenopus Oocytes

Mood

Friesel

Daar

2002

Journal of Biological Chemistry

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The docking protein SNT1/FRS2 (fibroblast growth factor receptor substrate 2) is implicated in the transmission of extracellular signals from the fibroblast growth factor receptor (FGFR), which plays vital roles during embryogenesis. Activating FGFR mutations cause several craniosynostoses and dwarfism syndromes in humans. Here we show that the Xenopus homolog of mammalian FRS-2 (XFRS2) is essential for the induction of oocyte maturation by an XFGFR1 harboring an activating mutation (XFGFR1act). Using a dominant-negative form of kinase suppressor of Ras, we show the Mek activity is required for germinal vesicle breakdown (GVBD) induced by co-expression of XFGFR1act and XFRS2, but this activity is not required for progesterone-induced GVBD. Furthermore, Mek/MAPK activity is critical for the induction and/or maintenance of H1 kinase activity at metaphase of meiosis II in progesterone-treated oocytes. An activated XFGFR1 containing a mutation in the phospholipase C␥ binding site (XFGFR1actY672F) displayed a reduced ability to induce cell-cycle progression in oocytes, suggesting phospholipase C␥ may not be necessary but that it augments XFGFR signaling in this system. Oocytes co-expressing XFGFR1act and XFRS2 showed substantial H1 kinase activity, but this activity was blocked when the oocytes were treated with the phosphatidylinositol 3-kinase inhibitor LY294002. Although phosphatidylinositol 3-kinase activity is essential for XFGFR1act/XFRS2-induced oocyte maturation, this activity is not required for maturation induced by progesterone. Finally, ectopic expression of Xspry2, a negative regulator of XFGFR signaling, greatly reduced MAPK activation and GVBD induced by the expression of either XFGFR1act plus XFRS2 or activated Ras (H-RasV12). In contrast, Xspry2 did not prevent GVBD induced by an activated form of Raf1, suggesting that Xspry2 exerts its inhibitory function upstream or parallel to Raf and downstream of Ras.

show abstract

tpr-met oncogene product induces maturation-producing factor activation in Xenopus oocytes.

Cited by 15 publications

References 35 publications

A single amino acid change in Raf-1 inhibits Ras binding and alters Raf-1 function.

A single amino acid change in Raf-1 inhibits Ras binding and alters Raf-1 function.

Initiation of Xenopus Oocyte Maturation by Activation of the Mitogen-activated Protein Kinase Cascade

SNT1/FRS2 Mediates Germinal Vesicle Breakdown Induced by an Activated FGF Receptor1 in Xenopus Oocytes

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