A POSTDOCTORAL POSITION is currently available for research on elucidation
of the N-mediated signal transduction pathways leading to TMV resistance.
We isolated the first virus resistance gene, N, of plants {Whitham
et al. (1994) Cell 78, 1101-1115}. The N gene confers resistance to
tobacco mosaic virus (TMV) in tobacco. To elucidate the mechanisms of
N-mediated resistance we are investigating: (1) regulation of N gene
expression, (2) the structure-function relationship of the N encoded
protein domains, (3) the structure, biochemical properties and cellular
localization of the N protein (4) the identification of TMV protein
required for N induced resistance (5) identification of components of the
resistance signal transduction pathway by genetic dissection of N
resistance pathway and identification of cellular interacting proteins, and
(7) identification of genes with structural and functional similarities to
N for comparative studies. The applicant will have the opportunity to
participate in one or more of these projects, however, the available
position primarily concerns genetic dissection of the N-mediated signal
transduction pathway in tobacco, tomato and Arabidopsis.
N is a member of the TIR-NBS-LRR class of R genes. The sequence of
several recently isolated R genes shows that they encode deduced products
with strikingly similar structural features {Baker et al. (1997) Science
276,726-733}. It is postulated that R genes encode receptors or components
of signaling pathways that participate in pathogen recognition and
signaling leading to cell death (hypersensitive response-HR), systemic
defense (systemic acquired resistance-SAR) and pathogen inhibition.
The amino-terminal domain of N (TIR) and other members of this
class of R genes share homology with the cytoplasmic domains of the
interleukin-1 receptor (Il-1R) the Drosophila and human Toll receptor
proteins, participants in pathogen defense programs. The sequence
similarity of N, IL-1R and Toll suggests that N mediates pathogen
resistance through an IL-1R/Toll-like signal transduction pathway. The
nucleotide binding site domain (NBS) of N and other R genes is homologous
to the putative ATPase domain of the caspase activating proteins CED-4 and
Apaf-1, proteins that regulate apoptosis in C. elegans and mammals
respectively. The sequence similarity of N and other R genes to CED-4 and
Apaf-1 suggests there may be similarities between mechanisms of cell death
in plants and animals {Chinnaiyan et al. (1997) Nature 388, 728-729}.
Applicants should have experience in genetics, biochemistry, molecular
biology and/or cell biology, however, prior work with plants is not
required. A cover letter describing research experience and interests, a
curriculum vitae and names of three references should be sent to: Dr.
Barbara Baker, University of California, Berkeley and USDA, Plant Gene
Expression Center, 800 Buchanan St., Albany, CA 94710. FAX: 510-559-5929 or
510-559-5678; email: bbaker at socrates.berkeley.edu
Barbara Baker
Plant Gene Expression Center
Department of Plant and Microbial Biology
University of California, Berkeley
& USDA-ARS
800 Buchanan St.
Albany, CA 94710
bbaker at socrates.berkeley.edu
Fax: 510-559-5678