Membrane biology

Michael T Marty

Assistant Professor, Chemistry and Biochemistry-Sci
Assistant Professor, Chemistry and Biochemistry - Med
Assistant Professor, BIO5 Institute
Primary Department
Department Affiliations
Contact
(520) 621-1501

Work Summary

The Marty Lab uses mass spectrometry to study interactions of membrane proteins, peptides, and lipids within nanoscale membrane mimetics.

Research Interest

Membrane proteins play a number of critical biochemical roles and make up the majority of drug targets. Despite their importance, membrane proteins remain challenging systems for analysis due to their amphipathic nature and low expression levels. Moreover, the lipid bilayer can play an important but largely unexplored role in regulating membrane protein structure and function. New analytical and biochemical methods are necessary to better understand and design drugs to target membrane proteins.

Xianchun Li

Professor, Entomology
Professor, Entomology / Insect Science - GIDP
Professor, BIO5 Institute
Primary Department
Department Affiliations
Contact
(520) 626-1749

Work Summary

Xianchun Li's research aims to use genetics to shed light on the defense signaling of plants and the counterdefense of herbivorous insects, which may result in the design of new insecticides for crops like corn, in defense against the corn earworm. Additionally, Dr. Li's research is to define, globally, the regulatory triangle between nuclear receptors (NRs), their ligands, and cytochrome P450s (P450s) in Drosophila melanogaster, and to investigate the molecular mechanisms of Bt and conventional insecticide resistance.

Research Interest

Xianchun Li, PhD, is interested in understanding the physiological, biochemical, molecular and evolutionary bases of fundamental processes in the life history of insects such as embryonic polarity, metamorphosis, developmental commitment, host usage and environmental adaptation. One focus of his research is to elucidate the reciprocal signaling interactions between plants and insects, and the resulted on-going defense (in the case of plants) / counterdefense (in the case of herbivorous insects) phenotypic arm race over ecological time scale, with emphasis on the genetic machinery that percepts and transduces the reciprocal cues into genome and regulate defense / counterdefense phenotypes. Working systems include Helicoverpa zea, the corn earworm, a polyphagous noctuide of economic importance, and Drosophila melanogaster, the fruit fly, a model organism. State of arts and traditional techniques are combining to identify the cues and to uncover the signaling transduction cascade that links environmental cues, gene expression and the resulted defense/counterdefense phenotypes. This research may lead to characterization of genes for designing new insecticides and/or genetically modifying crops. The second focus of Dr. Li’s research is to define, globally, the regulatory triangle between nuclear receptors (NRs), their ligands, and cytochrome P450s (P450s) in Drosophila melanogaster. Nuclear receptors (NRs) constitute a transcription factor superfamily that has evolved to sense and bind endogenous (e.g., hormones) and/or exogenous (e.g., naturally-occurring or synthetic xenobiotics) signal compounds, resulting in differential expression of particular target genes, which underlies a range of fundamental biological processes, including growth, development, reproduction, behavior, host usage, and environmental adaptation. Many of those cue chemicals, namely NR ligands, are synthesized and/or metabolized by members of the P450s gene superfamily, whose expression may be regulated by certain NRs. Bioinformatics analyses as well as systematic functional genomic techniques such as microarray, X-ChIP, mutation and ectopic expression will be combined to define the genome-wide regulatory interaction loops between NRs and P450s as well as to assign, at least partially, functions of individual NRs and P450s in the life history of fruit fly. Given the evolutionary conservations of homologous NRs and P450s between vertebrates and invertebrates, the results obtained in this project are expected to provide insights into the reciprocal regulatory interactions between NRs and P450s in other animals including humans as well as to provide great insights into new avenue for human NR ligand identification and NR-related drug design. The third focus of his research is to investigate the molecular mechanisms of Bt and conventional insecticide resistance, which is a major threat in current IPM system. In collaboration with Dr. Bruce Tabashnik, Timothy Dennehy, and Yves Carriere in our Department, Dr. Li is going to compare Bt toxin binding affinity and other defects of natural (s, r1, r2, r3) and artificial mutant PBW (Pink Bollworm) cadherin proteins and thus define the key functional domains of PBW cadherin.

Michael D L Johnson

Associate Professor, Applied BioSciences - GIDP
Associate Professor, BIO5 Institute
Associate Professor, Immunobiology
Member of the Graduate Faculty
Primary Department
Department Affiliations
Contact
(520) 626-3779

Work Summary

Metals such as calcium and iron are essential to living organisms. Some metals in excess, like copper, are detrimental to bacteria. My laboratory studies this phenomenon in Streptococcus pneumoniae to find novels method for killing pathogenic bacteria.

Research Interest

Metals serve as vital nutrients to all biological systems. During infections, bacteria must not only acquire all metals necessary for survival from within the host, such as calcium or manganese, but must also efflux metals that are toxic or in excess such as copper. The overall goal of my laboratory is to investigate how bacteria maintain homeostasis within the metal milieu. This goal involves determining how metals are processed, the orchestrated response during metal sensing, and the role that the host plays in this process during infection. Understanding how bacteria interact with metals during infections will identify novel therapeutic strategies against bacterial infections. Keywords: Infectious Diseases, Antibiotic resistance, Bacterial Pneumonia

Michael F Brown

Professor, Chemistry and Biochemistry-Sci
Professor, Applied Mathematics - GIDP
Professor, BIO5 Institute
Member of the General Faculty
Member of the Graduate Faculty
Primary Department
Department Affiliations
Contact
(520) 621-2163

Research Interest

Michael F. Brown is Professor of Chemistry & Biochemistry at the University of Arizona. He is co-director of the Biological Physics Program and the Chemical Physics Program, and was a co-founder of the Biological Chemistry Program at the University of Arizona. He is internationally renowned for his work on the molecular basis of activation of G-protein-coupled receptors that are the targets for the majority of pharmaceuticals and medicines used by humans. The focus of his work is on biomembranes, with a particular emphasis on lipid-protein interactions in relation to potential drug targets involving membrane proteins. He is involved with investigation of the molecular basis of visual signaling involving rhodopsin. Moreover, Professor Brown is an expert in nuclear magnetic resonance (NMR) spectroscopy. His activities in the area of biomolecular NMR spectroscopy involve the devolvement and application of methods for studying the structure and dynamics of biomolecules. Michael Brown has authored over 130 original research papers, 10 book chapters, 4 book reviews, and has published more than 275 abstracts. His current H-index is 43. He numbers among his coworkers various prominent scientists worldwide. He presents his work frequently at national and international conferences, and is the recipient of a number of major awards. Professor Brown's many contributions have established him as a major voice in the area of biomembrane research and biomolecular spectroscopy. He is frequently a member of various review panels and exerts an influence on science policy at the national level. Among his accolades, he is an elected Fellow of the American Association for the Advancement of Science; American Physical Society; Japan Society for the Promotion of Science; and the Biophysical Society. He is a Fellow of the Galileo Circle of the University of Arizona. Most recently, he received the Avanti Award of the Biophysical Society. This premier honor recognizes his vast and innovative contributions to the field of membrane biophysics, and groundbreaking work in the development of NMR techniques to characterize lipid structure and dynamics. Most recently he presented the 2014 Avanti lecture of the Biophysical Society.