Work in the Green Lab is centered on the ribosome. The overall fidelity of protein synthesis appears to be limited by the action of the ribosome, which is the two-subunit macromolecular machine responsible for decoding and translating messenger RNAs (mRNAs) into protein in all organisms. Our work is divided into four general project areas. The longest-standing research area concerns the interactions of eubacterial ribosomes and release factors. The goal is to understand the mechanism of action of release factors on the ribosome. A second research area involves biochemical and structure/function studies of the miRNA pathway, particularly the mechanism of action of the Argonaute proteins and their interacting factors. A third area of work in the lab is centered around regulation of eukaryotic translation, specifically in understanding the mechanism behind various mRNA quality control pathways and the interactions of proteins therein, as well as with the ribosome. The newest area of research in the lab extends our strengths in ribosome biochemistry to characterize the translation status of the cell using the ribosome profiling. We are using this technique to better understand the role of several factors involved in eukaryotic and prokaryotic translation fidelity.

The David Graham Lab studies the consequences of HIV interactions with the immune system, the resulting pathogenesis and how to sabotage these interactions. We apply advanced technologies like mass spectrometry to dissect processes at the molecular level. We are also actively involved in cardiovascular research and studies the ways proteins are organized into functional units in different cell types of the heart. Major projects in our lab are organized into three major areas: (1) H/SIV pathogenesis and neuropathogenesis, (2) Cardiovascular disease, and (3) High technology development

The Zhu lab is focused on characterizing the activities of large collection of proteins, building signaling networks for better understanding the mechanisms of biological processes, and identifying biomarkers in human diseases and cancers. More specifically, our group is interested in analyzing protein posttranslational modifications, and identifying important components involved in transcription networks and host-pathogen interactions on the proteomics level, and biomarkers in human IBD diseases.

Work in the William B. Guggino Lab focuses on the structure of the cystic fibrosis transmembrane conductance regulator (CFTR) and water channels; the molecular structure of transport proteins in epithelial cell membranes; and gene therapies to treat cystic fibrosis (CF) patients. We are also working to identify CF’s specific defect in chloride channel regulation. One recent study showed that insulin-like growth factor 1 (IGF-1) enhances the protein expression of CFTR.

Work in the Wei Dong Gao Lab primarily focuses on heart failure and defining molecular and cellular mechanisms of contractile dysfunction. We use molecular biology and proteomic techniques to investigate the changes that myofilament proteins undergo during heart failure and under drug therapy. We're working to determine the molecular nature of nitroxyl (HNO) modification of tropomyosin.

The Landon King Lab studies aquaporins water-specific membrane channel proteins. We hope to understand how these proteins contribute to water homeostasis in the respiratory tract and how their expression or function may be altered in disease states.

Research in the Wilson Lab focuses on three components of nuclear lamina structure: lamins, LEM-domain proteins (emerin), and BAF. These three proteins all bind each other directly, and are collectively required to organize and regulate chromatin, efficiently segregate chromosomes and rebuild nuclear structure after mitosis. Mutations in one or more of these proteins cause a variety of diseases including Emery-Dreifuss muscular dystrophy (EDMD), cardiomyopathy, lipodystrophy and diabetes, and accelerated aging. We are examining emerin's role in mechanotransduction, how emerin and lamin A are regulated, and whether misregulation contributes to disease.

Ion channels are pore-forming membrane proteins gating the flow of ions across the cell membrane. Among their many functions, ion channels regulate cell volume, control epithelial fluid secretion, and generate the electrical impulses in our brain. The Qiu Lab employs a multi-disciplinary approach including high-throughput functional genomics, electrophysiology, biochemistry, and mouse genetics to discover novel ion channels and to elucidate their role in health and disease.

The O’Rourke Lab uses an integrated approach to study the biophysics and physiology of cardiac cells in normal and diseased states. Research in our lab has incorporated mitochondrial energetics, Ca2+ dynamics, and electrophysiology to provide tools for studying how defective function of one component of the cell can lead to catastrophic effects on whole cell and whole organ function. By understanding the links between Ca2+, electrical excitability and energy production, we hope to understand the cellular basis of cardiac arrhythmias, ischemia-reperfusion injury, and sudden death. We use state-of-the-art techniques, including single-channel and whole-cell patch clamp, microfluorimetry, conventional and two-photon fluorescence imaging, and molecular biology to study the structure and function of single proteins to the intact muscle. Experimental results are compared with simulations of computational models in order to understand the findings in the context of the system as a whole. Ongoing studies in our lab are focused on identifying the specific molecular targets modified by oxidative or ischemic stress and how they affect mitochondrial and whole heart function. The motivation for all of the work is to understand • how the molecular details of the heart cell work together to maintain function and • how the synchronization of the parts can go wrong Rational strategies can then be devised to correct dysfunction during the progression of disease through a comprehensive understanding of basic mechanisms. Brian O’Rourke, PhD, is a professor in the Division of Cardiology and Vice Chair of Basic and Translational Research, Department of Medicine, at the Johns Hopkins University.

The Foster Lab uses the tools of protein biochemistry and proteomics to tackle fundamental problems in the fields of cardiac preconditioning and heart failure. Protein networks are perturbed in heart disease in a manner that correlates only weakly with changes in mRNA transcripts. Moreover, proteomic techniques afford the systematic assessment of post-translational modifications that regulate the activity of proteins responsible for every aspect of heart function from electrical excitation to contraction and metabolism. Understanding the status of protein networks in the diseased state is, therefore, key to discovering new therapies. D. Brian Foster, Ph.D., is an assistant professor of medicine in the division of cardiology, and serves as Director of the Laboratory of Cardiovascular Biochemistry at the Johns Hopkins University School of Medicine.