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Src homology 2 protein tyrosine phosphatase (SHPTP2)/Src homology 2 phosphatase 2 (SHP2) tyrosine phosphatase is a positive regulator of the interleukin 5 receptor signal transduction pathways leading to the prolongation of eosinophil survival.

Pazdrak K, Adachi T, Alam R - J. Exp. Med. (1997)

Bottom Line: We found that IL-5 produced a rapid activation and tyrosine phosphorylation of SHPTP2 within 1 min.The association of SHPTP2 with IL-5betacR was reconstituted using a synthetic phosphotyrosine-containing peptide, betac 605-624, encompassing tyrosine (Y)612.The binding to the phosphotyrosine-containing peptide increased the phosphatase activity of SHPTP2, whereas the same peptide with the phosphorylated Y612--> F mutation did not activate SHPTP2.

View Article: PubMed Central - PubMed

Affiliation: University of Texas Medical Branch, Department of Internal Medicine, Allergy and Immunology Division, Galveston, TX 77555-0762, USA.

ABSTRACT
Interleukin-5 (IL-5) regulates the growth and function of eosinophils. It induces rapid tyrosine phosphorylation of Lyn and Jak2 tyrosine kinases. The role of tyrosine phosphatases in IL-5 signal transduction has not been investigated. In this study, we provide first evidence that SH2 protein tyrosine phosphatase 2 (SHPTP2) phosphotyrosine phosphatase plays a key role in prevention of eosinophil death by IL-5. We found that IL-5 produced a rapid activation and tyrosine phosphorylation of SHPTP2 within 1 min. The tyrosine phosphorylated SHPTP2 was complexed with the adapter protein Grb2 in IL-5-stimulated eosinophils. Furthermore, SHPTP2 appeared to physically associate with beta common (betac) chain of the IL-5 receptor (IL-5betacR). The association of SHPTP2 with IL-5betacR was reconstituted using a synthetic phosphotyrosine-containing peptide, betac 605-624, encompassing tyrosine (Y)612. The binding to the phosphotyrosine-containing peptide increased the phosphatase activity of SHPTP2, whereas the same peptide with the phosphorylated Y612--> F mutation did not activate SHPTP2. Only SHPTP2 antisense oligonucleotides, but not sense SHPTP2, could inhibit tyrosine phosphorylation of microtubule-associated protein kinase, and reverse the eosinophil survival advantage provided by IL-5. Therefore, we conclude that the physical association of SHPTP2 with the phosphorylated betac receptor and Grb2 and its early activation are required for the coupling of the receptor to the Ras signaling pathway and for prevention of eosinophil death by IL-5.

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SHPTP2 antisense oligodeoxynucleotides inhibit IL-5– induced tyrosine phosphorylation of MAP/Erk2 kinase. Eosinophils were  cultured in the presence of 7.5 μM SHPTP2 antisense (AS) or sense (SS)  ODNs for 6 h, and then stimulated with IL-5 for 10 min. The cell lysates  were immunoprecipitated with anti-Erk2 Ab, resolved by SDS-PAGE,  and immunoblotted by an antiphosphotyrosine mAb (left) followed by  reprobing with anti-Erk-2 Ab (right). An increase in tyrosine phosphorylation of Erk2 was observed in eosinophils pretreated with sense ODN,  whereas pretreatment with antisense SHPTP2 significantly inhibited  IL-5–induced phosphorylation of MAP/Erk2 kinase. The blot is representative of three independent experiments.
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Figure 9: SHPTP2 antisense oligodeoxynucleotides inhibit IL-5– induced tyrosine phosphorylation of MAP/Erk2 kinase. Eosinophils were cultured in the presence of 7.5 μM SHPTP2 antisense (AS) or sense (SS) ODNs for 6 h, and then stimulated with IL-5 for 10 min. The cell lysates were immunoprecipitated with anti-Erk2 Ab, resolved by SDS-PAGE, and immunoblotted by an antiphosphotyrosine mAb (left) followed by reprobing with anti-Erk-2 Ab (right). An increase in tyrosine phosphorylation of Erk2 was observed in eosinophils pretreated with sense ODN, whereas pretreatment with antisense SHPTP2 significantly inhibited IL-5–induced phosphorylation of MAP/Erk2 kinase. The blot is representative of three independent experiments.

Mentions: Next we addressed the question of requirements of SHPTP2 phosphatase in IL-5–induced phosphorylation of MAP/Erk2 kinase. As shown in Fig. 9, there was significant reduction in MAP kinase tyrosine phosphorylation in eosinophils that were treated with the antisense ODNs. Since MAP kinase is considered a downstream molecule of the Ras signaling pathway, these results suggest that SHPTP2 plays a positive role in IL-5–induced activation of the Ras-MAP kinase pathway.


Src homology 2 protein tyrosine phosphatase (SHPTP2)/Src homology 2 phosphatase 2 (SHP2) tyrosine phosphatase is a positive regulator of the interleukin 5 receptor signal transduction pathways leading to the prolongation of eosinophil survival.

Pazdrak K, Adachi T, Alam R - J. Exp. Med. (1997)

SHPTP2 antisense oligodeoxynucleotides inhibit IL-5– induced tyrosine phosphorylation of MAP/Erk2 kinase. Eosinophils were  cultured in the presence of 7.5 μM SHPTP2 antisense (AS) or sense (SS)  ODNs for 6 h, and then stimulated with IL-5 for 10 min. The cell lysates  were immunoprecipitated with anti-Erk2 Ab, resolved by SDS-PAGE,  and immunoblotted by an antiphosphotyrosine mAb (left) followed by  reprobing with anti-Erk-2 Ab (right). An increase in tyrosine phosphorylation of Erk2 was observed in eosinophils pretreated with sense ODN,  whereas pretreatment with antisense SHPTP2 significantly inhibited  IL-5–induced phosphorylation of MAP/Erk2 kinase. The blot is representative of three independent experiments.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2199030&req=5

Figure 9: SHPTP2 antisense oligodeoxynucleotides inhibit IL-5– induced tyrosine phosphorylation of MAP/Erk2 kinase. Eosinophils were cultured in the presence of 7.5 μM SHPTP2 antisense (AS) or sense (SS) ODNs for 6 h, and then stimulated with IL-5 for 10 min. The cell lysates were immunoprecipitated with anti-Erk2 Ab, resolved by SDS-PAGE, and immunoblotted by an antiphosphotyrosine mAb (left) followed by reprobing with anti-Erk-2 Ab (right). An increase in tyrosine phosphorylation of Erk2 was observed in eosinophils pretreated with sense ODN, whereas pretreatment with antisense SHPTP2 significantly inhibited IL-5–induced phosphorylation of MAP/Erk2 kinase. The blot is representative of three independent experiments.
Mentions: Next we addressed the question of requirements of SHPTP2 phosphatase in IL-5–induced phosphorylation of MAP/Erk2 kinase. As shown in Fig. 9, there was significant reduction in MAP kinase tyrosine phosphorylation in eosinophils that were treated with the antisense ODNs. Since MAP kinase is considered a downstream molecule of the Ras signaling pathway, these results suggest that SHPTP2 plays a positive role in IL-5–induced activation of the Ras-MAP kinase pathway.

Bottom Line: We found that IL-5 produced a rapid activation and tyrosine phosphorylation of SHPTP2 within 1 min.The association of SHPTP2 with IL-5betacR was reconstituted using a synthetic phosphotyrosine-containing peptide, betac 605-624, encompassing tyrosine (Y)612.The binding to the phosphotyrosine-containing peptide increased the phosphatase activity of SHPTP2, whereas the same peptide with the phosphorylated Y612--> F mutation did not activate SHPTP2.

View Article: PubMed Central - PubMed

Affiliation: University of Texas Medical Branch, Department of Internal Medicine, Allergy and Immunology Division, Galveston, TX 77555-0762, USA.

ABSTRACT
Interleukin-5 (IL-5) regulates the growth and function of eosinophils. It induces rapid tyrosine phosphorylation of Lyn and Jak2 tyrosine kinases. The role of tyrosine phosphatases in IL-5 signal transduction has not been investigated. In this study, we provide first evidence that SH2 protein tyrosine phosphatase 2 (SHPTP2) phosphotyrosine phosphatase plays a key role in prevention of eosinophil death by IL-5. We found that IL-5 produced a rapid activation and tyrosine phosphorylation of SHPTP2 within 1 min. The tyrosine phosphorylated SHPTP2 was complexed with the adapter protein Grb2 in IL-5-stimulated eosinophils. Furthermore, SHPTP2 appeared to physically associate with beta common (betac) chain of the IL-5 receptor (IL-5betacR). The association of SHPTP2 with IL-5betacR was reconstituted using a synthetic phosphotyrosine-containing peptide, betac 605-624, encompassing tyrosine (Y)612. The binding to the phosphotyrosine-containing peptide increased the phosphatase activity of SHPTP2, whereas the same peptide with the phosphorylated Y612--> F mutation did not activate SHPTP2. Only SHPTP2 antisense oligonucleotides, but not sense SHPTP2, could inhibit tyrosine phosphorylation of microtubule-associated protein kinase, and reverse the eosinophil survival advantage provided by IL-5. Therefore, we conclude that the physical association of SHPTP2 with the phosphorylated betac receptor and Grb2 and its early activation are required for the coupling of the receptor to the Ras signaling pathway and for prevention of eosinophil death by IL-5.

Show MeSH
Related in: MedlinePlus