Robert Brooker

Research Interests:

An essential characteristic of living cells is their ability to transport specific
solutes across a semi-permeable membrane. An important pathway for the
uptake of many different types of hydrophilic solutes is via membrane bound
proteins which function as cation/solute cotransporters or symporters. This
type of transporter is able to cotransport a solute with a cation so that the
energy within a cation electrochemical gradient can be harnessed to drive
the secondary active transport of the solute.

The Brooker research lab is interested in the transport of ions and small
molecules across cellular membranes. They study two different categories
of transporters: sugar transporters and metal transporters. Both categories
are symporters that couple the uptake of the solute with the uptake
of hydrogen ions.

With regard to sugar transport, the lab has focused on the lactose permease
found in E. coli. Current studies involve an analysis of permease structure
and function using genetic approaches and biophysical approaches. The
metal transporters that are studied are involved in the uptake of iron (Fe+2)
and manganese (Mn+2) into cells. They are part of the NRAMP family that
is found in bacteria, plants, and animals. With regard to mammals, NRAMP
transporters are found in intestinal cells and are needed for the uptake
of iron into the body. Human genetic diseases are known which affect
the regulation of iron transporters. The study of iron transporters
is directed in several areas. These include regulation, structure/function,
and their potential role in human disease.

Selected Publications:

Peter J. Franco, Elizabeth A. Matzke, Jerry L. Johnson, Brian M. Wiczer and Robert J. Brooker (2006) A suppressor analysis of residues involved proton transport in the lactose permease: Identification of a coupling sensor. J Membr Biol. 2006;211(2):101-13.

Haemig HAH, and RJ Brooker (2004) Importance fo Conserved Acidic Residues in MntH, and Nramp homolog of Escherichia coli. J. Membrane Biol 201: 97-107

Johnson JL and RJ Brooker (2004) Control of H+/Lactose Coupling by Ionic Interactions in the Lactose Permease of Escherichia coli. J. Membrane Biol. 198: 135-46.

Johnson, J.L., and R.J. Brooker (2003) Role of Glu-126 and Arg-144 in the Lactose Permease of Escherichia coli. Biochemistry, in press.

Patzlaff JS. Zhang J. Brooker RJ. Barry BA. (2002) An isotope-edited FT-IR study of a symporter, the lactose permease. Biochemistry 41, 7366-72.

Green, A.L., and R.J. Brooker (2001) A face on transmembrane segment 8 of the lactose permease is important for transport activity. Biochemistry 40, 12220-9.

Johnson, J.L., Lockheart M.S. and R.J. Brooker (2001) A Triple Mutant, K319N/H322Q/E325. of the Lactose Permease Cotransports H+ with Thiodigagalactoside. J. Memb. Biol. 181, 215-224.

Pazdernik,N.J., Matzke, E.A., Jessen-Marshall, A.E., and R.J. Brooker (2000) Roles of Charged Residues in the Conserved Motif, G-X-X-X-D/E-R/K-X-G-[X]-R/K-R/K,of the Lactose Permease of,Escherichia coli. J. Memb. Biol. 174, 31-40.

Green, A.L., Anderson, E., and R.J. Brooker (2000) A Revised Model for the Structure and Function of the Lactose Permease. Evidence that a Face on Transmembrane Segment 2 Is Important for Conformational Changes. J. Biol. Chem. 275, 23, 240-23,246.

Patzlaff, J.S., Brooker, R.J., and B.A. Barry (2000) A Reaction-induced Fourier Transform-Infrared Spectroscopic Study of the Lactose Permease. J. Biol. Chem. 275,28,695-28,000.
 

To view these and other publications visit http://www.ncbi.nlm.nih.gov/PubMed
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