Circulating platelets are primed to respond very rapidly to thrombogenic stimuli, but most platelets complete their lifespan without ever becoming activated. Platelet activation is accompanied by waves of sequential tyrosine phosphorylation thought to involve members of the Src family of protein tyrosine kinases (PTKs). We show here that resting platelets contain highly active pp53/56(Lyn) PTK ...

Dysfunction of pancreatic beta-cells is a fundamental feature in the pathogenesis of type 2 diabetes. As insulin receptor signaling occurs via protein tyrosine kinase (PTK), we investigated the role of PTK activity in the etiology of beta-cell dysfunction by inhibiting PTK activity in primary cultured mouse pancreatic beta-cells and INS-1 cells with genistein treatment over 24 h. Electrophysiol...

AIMS To evaluate the therapeutic effects of excimer laser phototherapeutic keratectomy (PTK) combined with therapeutic contact lens for painful recurrent corneal erosions (RCE) secondary to bullous keratopathy (BK) not suitable for penetrating keratoplasty. METHODS Excimer laser PTK was performed prospectively in eight eyes with painful RCE due to BK visually expecting no benefit from penetra...

Malignant pleural effusion (PE) is associated with advanced human lung cancer. We found recently, using a nude mouse model, that vascular endothelial growth factor/vascular permeability factor (VEGF/VPF) is responsible for PE induced by non-small cell human lung carcinoma cells. The purpose of this study was to determine the therapeutic potential of a VEGF/VPF receptor tyrosine kinase phosphory...

OBJECTIVE To evaluate the outcome of phototherapeutic keratectomy (PTK) treatment of epithelial basement membrane dystrophy (EBMD) patients and to examine clinical and morphologic signs of recurrent dystrophy. DESIGN Cross-sectional, clinic-based study. PARTICIPANTS Fifty-two eyes of 39 patients diagnosed with EBMD who underwent PTK between 2001 and 2008. METHODS Preoperative symptoms, be...

The lymphoid-specific Src family protein tyrosine kinase p56lck (Lck) is non-covalently associated with the cytoplasmic tail of CD4 and has an essential role in T cell activation. Engagement of ligand by the T cell antigen receptor (TCR) is followed by rapid tyrosine phosphorylation of several cellular proteins, including phospholipase C gamma 1 (PLC) and the TCR-associated CD3 zeta polypeptide...

Anaplastic lymphoma kinase (ALK) is a receptor tyrosine kinase essentially and transiently expressed in specific areas of the developing central and peripheral nervous systems. We previously demonstrated that a membrane-bound and constitutively active form of the ALK protein tyrosine kinase (PTK) domain induced the neuron-like differentiation of PC12 cells through specific activation of the mit...

The role of protein tyrosine kinase (PTK) activity in the development of the retinal projection was examined in vivo by applying inhibitors of cytoplasmic PTKs, herbimycin A and lavendustin A, to intact brain preparations of Xenopus embryos. The inhibitors were present during the period when retinal ganglion cell axons first navigate through the optic tract to reach their target, the optic tect...

IP3 increase and de novo synthesis of scoparone are produced in the hypersensitive response (HR) of lemon seedlings against the fungus Alternaria alternata. To elucidate whether a G-protein and/or a protein tyrosine kinase (PTK) are involved in signal transduction leading to the production of such a defensive response, we studied the HR in this plant system after treatment with G-protein activa...

A 52 kd cellular protein, FK506-binding protein (FKBP52), phosphorylated at tyrosine residues by epidermal growth factor receptor protein tyrosine kinase (EGFR-PTK), inhibits adeno-associated virus 2 (AAV2) second-strand DNA synthesis and transgene expression. FKBP52 is dephosphorylated at tyrosine residues by T-cell protein tyrosine phosphatase (TC-PTP), and TC-PTP over-expression leads to imp...