MSK
Search
- Page Path
- HOME > Search
- Nitric oxide in human cytomegalovirus replication and gene expression
- Lee, Jee Yeon , Lee, Chan Hee
- J. Microbiol. 1997;35(2):152-157.
- 17 View
- 0 Download
-
Abstract
- Infection of human fibroblast (HF) cells with human cytomegalovirus (HCMV) result in changes in the intracellular level of second messengers. Since nitric oxide (NO) production has been known to be related with other second messengers, it is probable that HCMV infection of HF cells may involve NO. To test this possibility, the amount of NO was measured following HCMV infection but we were not able to detect significant change in the production of NO. Exogenous addition of NO generators such as sodium nitroprusside (SNP) or S-nitroso-N-a-cetylpenicillamine (SNAP) immediately after HCMV infection, however, inhibited virus multiplication. Furthermore, immunoblot experiment using monoclonal antibody to HCMV major immediate early (MIE) proteins or CAT assay using pCMVIE/CAT (plasmid containing CAT gene driven by HCMV MIE promoter) revealed that SNP or SNAP blocked the MIE gene expression. SNP was more effective than SNAP in hibiting HCMV multiplication or MIE gene expression. SNP produced more NO than SNAP in inhibiting HCMV multiplication or MIE gene expression. SNP produced more NO than SNAP. Although the mechanism for the inhibition of HCMV multiplication and MIE gene expression by NO is still elusive some correlation with NO-mediated inhibition of HCMV-induced increase in cytosolic free Ca^2+ concentration ([Ca^2+]) was observed. The increase of [Ca^2+] following HCMV infection was inhibited by SNP, and less effectively by SNAP. Raising [Ca^2+ with bromo-A23187 partially reversed the SNP block of MIE gene expression. Thus, there appear to e some relationships among NO. [Ca^2+], and HCMV MIE gene expression.
- Purification and Properties of Novel Calcium-binding Proteins from Streptomyces coelicolor
- Chang, Ji Hun , Yoon, Soon Sang , Lhee, Sang Moon , Park, I Ha , Jung, Do Young , Park, Yong Sik , Yim, Jeong Bin
- J. Microbiol. 1999;37(1):21-26.
- 13 View
- 0 Download
-
Abstract
- Two novel calcium-binding proteins, named CAB-I and CAB-II, have been isolated from Streptomyces coelicolor. Purification of the calcium-binding proteins involved heat treatment, fractionation with ammonium sulfate, acid treatment, anion exchange and hydrophobic interaction column chromatography, FPLC gel filtration, and preparative isoelectric focusing. A chelex competitive assay and ^45Ca autoradiography verified the calcium-binding ability of the proteins. The major band CAB-II has an apparent molecular weight of 26,000 determined by SDS-polyacrylamide gel electrophoresis and 340,000 determined by gel filtration. The isoelectric point of this molecule showed the acidic nature of the molecule. N-terminal amino acid sequence analysis shows homology to rat Ca^2+/calmodulin-dependent protein kinase-II (CAB-II) and yeast phosphoprotein phosphatase (CAB-I).
First
Prev
TOP
