ABE Akio Kitasato Institute Besearch Institute, 基礎研究所, 主任研究員 (50184205)
NAGAI Masaaki Kitasato University, Dept of Pharmaceutical Sciences, Assostant, 薬学部, 助手 (10198294)
SEKIYA Kachuko Kitasato University, Dept of Pharmaceutical Sciences, 薬学部, 講師 (30050579)
ENDOH Masahiko Kitasato University, Dept of Pharmaceutical Sciences, 薬学部, 助教授 (60104519)
|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1994 : ¥800,000 (Direct Cost : ¥800,000)
Fiscal Year 1993 : ¥1,300,000 (Direct Cost : ¥1,300,000)
Our previous studies showed that S.Choleraesuis strain RF-1 isolated from septicemic pig harbors 50kb-virulence plasmid designated pKDSC50, and the 6.4kb SalI-EcoRI region of pKDSC50 encompassing four spv genes, spvR,spvA,spvB,and spvC,is essential to produce systemic disease in pigs and mice. The spvR gene was characterized as a positive activator gene for transcription of the following three genes, spvA,spvB,and spvC.The aim of the present study is to obtain the basic knowledges of Spv proteins which are requird for understanding the Salmonella systemic infection.
1. Regulatory function of Spv proteins
SpvR is a positive regulatory protein for the expression of its own gene, spvR.SpvA and SpvBare negative regulatory proteins for the expression of spvR gene. spvR gene is expressed in RpoS-dependent manner at the stationary phase of bacterial growth.
2. Isolation, purification, and characterization of Spv proteins
The four Spv proteins, spvR,spvA,spvB,and spvC were partially purified from S.Choleraesuis strain RF-1. Molecular weight of the purified Spv proteins by SDS-PAGE was determinded as 31 kDa for SpvR,26 kDa for SpvA,73 kDa for SpvB,and 24 kDa for SpvC.It was demonstrated that SpvB is a hydrophobic protein, and SpvC is a basic protein.
3. Immunoelectron microscopic localization of Spv proteins
A method for the localizatiom of Spv proteins by immunoelectron microscopy was established. By using cryo ultra-thin section of S.Choleraesuis strain RF-1 fixed with periodete lysin-paraformaldehyde, SpvC was revealed to be a cytoplasmic and outer menbrane protein. The localization of SpvR,SpvA,and SpvB proteins is under investigation.