With increasing age, NHE1 TG mice exhibited increased myocyte apoptosis, developed left ventricular contractile dysfunction, underwent cardiac remodelling and died prematurely. Our findings indicate that: (1) Cardiac-specific NHE1 over-expression induces the ER stress response in mouse myrocardium, which may afford protection against ischemia/reperfusion-induced injury despite increased NHE activity; (2) Ageing NHE1 TG mice exhibit myocyte apoptosis, cardiac remodelling and failure, likely as a result of Sustained ER stress; (3) The pluripotent effects of the ER stress response may confound studies that are based on the chronic over-expression of complex
proteins in myrocardium. (C) 2008 Elsevier Inc. Stem Cell Compound Library All rights reserved.”
“Recruitment of the growth factor receptor-bound protein 2 (Grb2) by the plasma membrane-associated adapter protein downstream of kinase 3 (Dok-3) attenuates signals transduced by the B cell antigen receptor (BCR). Here we describe molecular details of Dok-3/Grb2 signal integration and function, showing that the Lyn-dependent
activation of the BCR transducer kinase Syk is attenuated by Dok-3/Grb2 in a site-specific manner. This process is associated with the SH3 domain-dependent translocation of Dok-3/ Grb2 complexes into BCR microsignalosomes and augmented phosphorylation of the inhibitory Lyn target HSP990 in vitro SH2 domain-containing inositol 5′ phosphatase. Hence, our findings imply that Dok-3/ Grb2 modulates the balance between activatory and inhibitory Lyn functions selleck chemicals llc with the aim to adjust BCR signaling efficiency.”
“Background: Retroviral integrase catalyzes integration of viral DNA into the host genome. Integrase interactor (INI) 1/hSNF5 is a host factor that binds to HIV-1 IN within the context of Gag-Pol and is specifically incorporated into HIV-1 virions during assembly. Previous studies have indicated that INI1/hSNF5 is required for late events in vivo and for integration in vitro. To determine the effects of disrupting the IN-INI1 interaction
on the assembly and infectivity of HIV-1 particles, we isolated mutants of IN that are defective for binding to INI1/hSNF5 and tested their effects on HIV-1 replication.\n\nResults: A reverse yeast two-hybrid system was used to identify INI1-interaction defective IN mutants (IID-IN). Since protein-protein interactions depend on the surface residues, the IID-IN mutants that showed high surface accessibility on IN crystal structures (K71R, K111E, Q137R, D202G, and S147G) were selected for further study. In vitro interaction studies demonstrated that IID-IN mutants exhibit variable degrees of interaction with INI1. The mutations were engineered into HIV-1(NL4-3) and HIV-Luc viruses and tested for their effects on virus replication.