Abstract

All cellular organisms respond to vibration, touch, gravity, or changes in osmolarity, but the molecular bases of such mechano-sensations are unknown. Candidate molecules include certain ion channels, such as the mechano-sensitive channel of very large conductance (MscL) of Escherichia coli observed by patch-clamp experiments. We used a functional test to identify MscL as a l7-kD protein and cloned the corresponding gene, mscL. The sequence indicates a unique protein of 136 amino acid, highly hydrophobic, and rich in P structure. We plan to find mscL homologues in other species and to define the conserved regions. We will then generate chimeras and site-directed mutants as well as selected mutants to define the amino-acid residues or peptide regions responsible for solute permeability and mechano-sensitivity. By combining recombinant DNA technology and patch-clamp analysis, we hope to understand the molecular structure/function relation of this unique mechanosensitive protein.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM047856-04
Application #
2415173
Study Section
Microbial Physiology and Genetics Subcommittee 2 (MBC)
Project Start
1994-05-01
Project End
1998-04-30
Budget Start
1997-05-01
Budget End
1998-04-30
Support Year
4
Fiscal Year
1997
Total Cost
Indirect Cost

  Institution

Name
University of Wisconsin Madison
Department
Biochemistry
Type
Other Domestic Higher Education
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715

  Publications

Loukin, Stephen; Su, Zhenwei; Kung, Ching (2011) Increased basal activity is a key determinant in the severity of human skeletal dysplasia caused by TRPV4 mutations. PLoS One 6:e19533
Loukin, Stephen; Zhou, Xinliang; Su, Zhenwei et al. (2010) Wild-type and brachyolmia-causing mutant TRPV4 channels respond directly to stretch force. J Biol Chem 285:27176-81
Kung, Ching; Martinac, Boris; Sukharev, Sergei (2010) Mechanosensitive channels in microbes. Annu Rev Microbiol 64:313-29
Su, Zhenwei; Zhou, Xinliang; Loukin, Stephen H et al. (2009) Mechanical force and cytoplasmic Ca(2+) activate yeast TRPY1 in parallel. J Membr Biol 227:141-50
Loukin, Stephen H; Su, Zhenwei; Kung, Ching (2009) Hypotonic shocks activate rat TRPV4 in yeast in the absence of polyunsaturated fatty acids. FEBS Lett 583:754-8
Martinac, Boris; Saimi, Yoshiro; Kung, Ching (2008) Ion channels in microbes. Physiol Rev 88:1449-90
Myers, Benjamin R; Saimi, Yoshiro; Julius, David et al. (2008) Multiple unbiased prospective screens identify TRP channels and their conserved gating elements. J Gen Physiol 132:481-6
Loukin, Stephen; Zhou, Xinliang; Kung, Ching et al. (2008) A genome-wide survey suggests an osmoprotective role for vacuolar Ca2+ release in cell wall-compromised yeast. FASEB J 22:2405-15
John Haynes, W; Zhou, Xin-Liang; Su, Zhen-Wei et al. (2008) Indole and other aromatic compounds activate the yeast TRPY1 channel. FEBS Lett 582:1514-8
Su, Zhenwei; Zhou, Xinliang; Haynes, W John et al. (2007) Yeast gain-of-function mutations reveal structure-function relationships conserved among different subfamilies of transient receptor potential channels. Proc Natl Acad Sci U S A 104:19607-12

Showing the most recent 10 out of 29 publications