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Full-Text Articles in Molecular Biology
Competition Between Ski And Creb-Binding Protein For Binding To Smad Proteins In Transforming Growth Factor-Beta Signaling, Weijun Chen, Suvana Lam, Hema Srinath, Celia Schiffer, William Royer, Kai Lin
Competition Between Ski And Creb-Binding Protein For Binding To Smad Proteins In Transforming Growth Factor-Beta Signaling, Weijun Chen, Suvana Lam, Hema Srinath, Celia Schiffer, William Royer, Kai Lin
Celia A. Schiffer
The family of Smad proteins mediates transforming growth factor-beta (TGF-beta) signaling in cell growth and differentiation. Smads repress or activate TGF-beta signaling by interacting with corepressors (e.g. Ski) or coactivators (e.g. CREB-binding protein (CBP)), respectively. Specifically, Ski has been shown to interfere with the interaction between Smad3 and CBP. However, it is unclear whether Ski competes with CBP for binding to Smads and whether they can interact with Smad3 at the same binding surface on Smad3. We investigated the interactions among purified constructs of Smad, Ski, and CBP in vitro by size-exclusion chromatography, isothermal titration calorimetry, and mutational studies. Here, …
Mass Spectrometry Analysis Of Hiv-1 Vif Reveals An Increase In Ordered Structure Upon Oligomerization In Regions Necessary For Viral Infectivity, Jared Auclair, Karin Green, Shivender Shandilya, James Evans, Mohan Somasundaran, Celia Schiffer
Mass Spectrometry Analysis Of Hiv-1 Vif Reveals An Increase In Ordered Structure Upon Oligomerization In Regions Necessary For Viral Infectivity, Jared Auclair, Karin Green, Shivender Shandilya, James Evans, Mohan Somasundaran, Celia Schiffer
Celia A. Schiffer
HIV-1 Vif, an accessory protein in the viral genome, performs an important role in viral pathogenesis by facilitating the degradation of APOBEC3G, an endogenous cellular inhibitor of HIV-1 replication. In this study, intrinsically disordered regions are predicted in HIV-1 Vif using sequence-based algorithms. Intrinsic disorder may explain why traditional structure determination of HIV-1 Vif has been elusive, making structure-based drug design impossible. To characterize HIV-1 Vif's structural topology and to map the domains involved in oligomerization we used chemical cross-linking, proteolysis, and mass spectrometry. Cross-linking showed evidence of monomer, dimer, and trimer species via denaturing gel analysis and an additional …
Exploring The Role Of The Solvent In The Denaturation Of A Protein: A Molecular Dynamics Study Of The Dna Binding Domain Of The 434 Repressor, Celia Schiffer, Volker Dötsch, Kurt Wuthrich, Wilfred Van Gunsteren
Exploring The Role Of The Solvent In The Denaturation Of A Protein: A Molecular Dynamics Study Of The Dna Binding Domain Of The 434 Repressor, Celia Schiffer, Volker Dötsch, Kurt Wuthrich, Wilfred Van Gunsteren
Celia A. Schiffer
Molecular dynamics simulations of the DNA binding domain of 434 repressor are presented which aim at unraveling the role of solvent in protein denaturation. Four altered solvent models, each mimicking various possible aspects of the addition of a denaturant to the aqueous solvent, were used in the simulations to analyze their effects on the stability of the protein. The solvent was altered by selectively changing the Coulombic interaction between water and protein atoms and between different water molecules. The use of a modified solvent model has the advantage of mimicking the presence of denaturant without having denaturant molecules present in …
Structural Analysis Of Human Immunodeficiency Virus Type 1 Crf01_Ae Protease In Complex With The Substrate P1-P6., Rajintha Bandaranayake, Moses Prabu-Jeyabalan, Junko Kakizawa, Wataru Sugiura, Celia Schiffer
Structural Analysis Of Human Immunodeficiency Virus Type 1 Crf01_Ae Protease In Complex With The Substrate P1-P6., Rajintha Bandaranayake, Moses Prabu-Jeyabalan, Junko Kakizawa, Wataru Sugiura, Celia Schiffer
Celia A. Schiffer
The effect of amino acid variability between human immunodeficiency virus type 1 (HIV-1) clades on structure and the emergence of resistance mutations in HIV-1 protease has become an area of significant interest in recent years. We determined the first crystal structure of the HIV-1 CRF01_AE protease in complex with the p1-p6 substrate to a resolution of 2.8 A. Hydrogen bonding between the flap hinge and the protease core regions shows significant structural rearrangements in CRF01_AE protease compared to the clade B protease structure.