The broad goals of this research are to extend our knowledge of how skeletal myoblasts form muscle fibers. Although much evidence demonstrates a critical role for protein tyrosine kinases (PTKs) in myogenesis, the role played by protein tyrosine phosphatases (PTPs) in this process is unknown. This grant focuses on how PTPs participate in three fundamental areas of myogenesis. First, how do PTPs participate in growth factor signaling pathways that negatively regulate myogenesis? Second, what is the contribution of PTPs to myogenic progression? Third, are PTPs involved in the mechanisms that mediate conversion of a mononucleated myocyte to a multinucleated myotube? Our preliminary data on the SH2 domain containing PTP (SHP 2) and the mitogen activated protein kinase (MAPK) phosphatase 1 (MKP 1), which function as positive and negative regulators of the MAPK pathway respectively, has led us to the following hypotheses: (1) MKP 1 functions as a critical mediator of multinucleated myotube formation and (2) that SHP 2 plays both a positive and negative signaling role in regulating myogenesis. Mutants of MKP 1 that form stable enzyme substrate complexes (substrate trapping mutants) will be utilized to identify the MAPK(s) involved in myotube formation. How SHP 2 participates in FGF 2 regulation of myogenesis will be determined. A combination of SHP 2 overexpression studies and SHP 2 """"""""loss of function"""""""" myoblasts will be used to elucidate its role in myogenic progression. Finally, we report that in myoblasts, SHP 2 interacts with the signal regulatory protein 1cc(SIRP 1a), a recently discovered member of a family of transmembrane glycoproteins. The protein expression and tyrosyl phosphorylation of SIRP 1 a are induced during myogenesis, prior to myotube formation. We will define the function of SIRP 1a by identifying its cellular localization both in cultured myoblasts during myogenic differentiation and in vivo in striated skeletal muscle. We will test whether the extracellular domain of SlRP 1a is involved in myotube formation and determine using anti sense methods its requirement for myogenic progression. Many musculoskeletal diseases, such as the myasthenic syndromes and muscular dystrophies, lead to muscle degeneration and atrophy. The information gained from this research can be harnessed to provide insight into new therapies designed to either prevent or retard these pathological conditions.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
5R01AR046504-03
Application #
6532994
Study Section
Cell Development and Function Integrated Review Group (CDF)
Program Officer
Lymn, Richard W
Project Start
2000-08-01
Project End
2005-07-31
Budget Start
2002-08-01
Budget End
2003-07-31
Support Year
3
Fiscal Year
2002
Total Cost
$320,512
Indirect Cost
Name
Yale University
Department
Pharmacology
Type
Schools of Medicine
DUNS #
082359691
City
New Haven
State
CT
Country
United States
Zip Code
06520
Shi, Hao; Verma, Mayank; Zhang, Lei et al. (2013) Improved regenerative myogenesis and muscular dystrophy in mice lacking Mkp5. J Clin Invest 123:2064-77
Shi, Hao; Boadu, Emmanuel; Mercan, Fatih et al. (2010) MAP kinase phosphatase-1 deficiency impairs skeletal muscle regeneration and exacerbates muscular dystrophy. FASEB J 24:2985-97
Flach, Rachel J Roth; Bennett, Anton M (2010) MAP kinase phosphatase-1--a new player at the nexus between sarcopenia and metabolic disease. Aging (Albany NY) 2:170-6
Jeanneteau, Freddy; Deinhardt, Katrin; Miyoshi, Goichi et al. (2010) The MAP kinase phosphatase MKP-1 regulates BDNF-induced axon branching. Nat Neurosci 13:1373-9
Yu, Luyang; Min, Wang; He, Yun et al. (2009) JAK2 and SHP2 reciprocally regulate tyrosine phosphorylation and stability of proapoptotic protein ASK1. J Biol Chem 284:13481-8
Carlson, Jodi; Cui, Weiguo; Zhang, Qing et al. (2009) Role of MKP-1 in osteoclasts and bone homeostasis. Am J Pathol 175:1564-73
Eminaga, Seda; Bennett, Anton M (2008) Noonan syndrome-associated SHP-2/Ptpn11 mutants enhance SIRPalpha and PZR tyrosyl phosphorylation and promote adhesion-mediated ERK activation. J Biol Chem 283:15328-38
Zito, Christina I; Qin, Hui; Blenis, John et al. (2007) SHP-2 regulates cell growth by controlling the mTOR/S6 kinase 1 pathway. J Biol Chem 282:6946-53
Uhlen, Per; Burch, Peter M; Zito, Christina Ivins et al. (2006) Gain-of-function/Noonan syndrome SHP-2/Ptpn11 mutants enhance calcium oscillations and impair NFAT signaling. Proc Natl Acad Sci U S A 103:2160-5
Fornaro, Mara; Burch, Peter M; Yang, Wentian et al. (2006) SHP-2 activates signaling of the nuclear factor of activated T cells to promote skeletal muscle growth. J Cell Biol 175:87-97

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