Negative regulation of EGFR signalling through integrin-alpha1beta1-mediated activation of protein tyrosine phosphatase TCPTP.
AuthorsMattila E, Pellinen T, Nevo J, Vuoriluoto K, Arjonen A, Ivaska J
JournalNat Cell Biol
PubMed ID15592458
'Integrin-mediated cell adhesion regulates a multitude of cellular responses, including proliferation, survival and cross-talk between different cellular signalling pathways. So far, integrins have been mainly shown to convey permissive signals enabling anchorage-dependent receptor tyrosine kinase signalling. Here we show that a collagen-binding integrin alpha(1)beta(1) functions as a negative regulator of ... More
Differential coupling of M1 muscarinic and alpha7 nicotinic receptors to inhibition of pemphigus acantholysis.
AuthorsChernyavsky AI, Arredondo J, Piser T, Karlsson E, Grando SA,
JournalJ Biol Chem
PubMed ID18073210
'The mechanisms mediating and regulating assembly and disassembly of intercellular junctions is a subject of intensive research. The IgG autoantibodies produced in patients with the immunoblistering skin disease pemphigus vulgaris (PV) can induce keratinocyte (KC) dyshesion (acantholysis) via mechanisms that involve signaling kinases targeting intercellular adhesion molecules, thus providing a ... More
Protein tyrosine phosphatase: enzymatic assays.
AuthorsMontalibet J, Skorey KI, Kennedy BP
JournalMethods
PubMed ID15588980
Activity assays for tyrosine phosphatases are based on the hydrolysis of a arylphosphate moiety from a synthetic substrate yielding a spectroscopically active product. Many different substrates can be used for these assays with p-nitrophenyl phosphate (pNPP), fluorescein diphosphate (FDP), and 6,8-difluoro-4-methylumbellyferyl phosphate (DiFMUP) being the most efficient and versatile. Equally, ... More
Chaperone release and unfolding of substrates in type III secretion.
AuthorsAkeda Y, Galán JE
JournalNature
PubMed ID16208377
Type III protein secretion systems are essential virulence factors of many bacteria pathogenic to humans, animals and plants. These systems mediate the transfer of bacterial virulence proteins directly into the host cell cytoplasm. Proteins are thought to travel this pathway in a largely unfolded manner, and a family of customized ... More
Development of fluorescence-based selective assays for serine/threonine and tyrosine phosphatases.
AuthorsPastula C, Johnson I, Beechem JM, Patton WF
JournalComb Chem High Throughput Screen
PubMed ID12769677
A number of aromatic substrates were evaluated for their ability to detect tyrosine phosphatase and serine/threonine phosphatase activity. Results demonstrated that the fluorinated coumarin DiFMUP is the most sensitive substrate for detecting LAR and PP-2A activity. Using this substrate, selective high-throughput screening assays for serine/threonine and tyrosine phosphatases were developed. ... More
The SHP-1 protein tyrosine phosphatase negatively modulates glucose homeostasis.
AuthorsDubois MJ, Bergeron S, Kim HJ, Dombrowski L, Perreault M, Fournès B, Faure R, Olivier M, Beauchemin N, Shulman GI, Siminovitch KA, Kim JK, Marette A
JournalNat Med
PubMed ID16617349
The protein tyrosine phosphatase SHP-1 is a well-known inhibitor of activation-promoting signaling cascades in hematopoietic cells but its potential role in insulin target tissues is unknown. Here we show that Ptpn6(me-v/me-v) (also known as viable motheaten) mice bearing a functionally deficient SHP-1 protein are markedly glucose tolerant and insulin sensitive ... More