Vaccinia virus A26 protein is an envelope protein of the intracellular mature virus (IMV) of vaccinia virus. A mutant A26 protein with a truncation of the 74 C-terminal amino acids was expressed in infected cells but failed to be incorporated into IMV (W. L. Chiu, C. L. Lin, M. H. Yang, D. L. Tzou, and W. Chang, J. Virol 81:2149–2157, 2007). Here, we demonstrate that A27 protein formed a protein complex with the full-length form but not with the truncated form of A26 protein in infected cells as well as in IMV. The formation of the A26-A27 protein complex occurred prior to virion assembly and did not require another A27-binding protein, A17 protein, in the infected cells. A26 protein contains six cysteine residues, and in vitro mutagenesis showed that Cys441 and Cys442 mediated intermolecular disulfide bonds with Cys71 and Cys72 of viral A27 protein, whereas Cys43 and Cys342 mediated intramolecular disulfide bonds. A26 and A27 proteins formed disulfidelinked complexes in transfected 293T cells, showing that the intermolecular disulfide bond formation did not depend on viral redox pathways... J. Virol 83:6464-6476,2009 Read more...

The I subunit of magnesium-chelatase (CHLI) is encoded by two genes in Arabidopsis (Arabidopsis thaliana), CHLI1 and CHLI2. Conflicting results have been reported concerning the functions of the two proteins. We show here that the chli1/chli1 chli2/chli2 double knockout mutant was albino. Comparison with the pale-green phenotype of a chli1/chli1 single knockout mutant indicates that CHLI2 could support some chlorophyll biosynthesis in the complete absence of CHLI1. Real-time quantitative reverse transcription-polymerase chain reaction showed that CHLI2 was expressed at a much lower level than CHLI1. The chli1/chli1 chli2/chli2 double mutant could be fully rescued by expressing a transgene of CHLI2 driven by the CHLI1 promoter. These results suggest that differences between CHLI1 and CHLI2 lie mostly in their expression levels. Furthermore, both the chli1/chli1 and chli2/chli2 single knockout mutants had lower survival rates during de-etiolation than the wild type, suggesting that both genes are required for optimal growth during de-etiolation... Plant Physiology 150, 636-645, 2009 Read more...

IE2 forms nuclear bodies in mammalian nucleus. These nuclear bodies could be viewed as novel sub-cellular factories for high level gene expression. Our discovery makes it possible for much improved humanized protein production using baculovirus vector in mammalian cells. (A) A confocal image of IE2 nuclear bodies (Blue) with Pol II (RED) (a) or IE2 (RED) with G-actin (GREEN) (b) are taken within a Vero E6 cell nucleus 20 hours post transduction by IE2 expressing-baculoviruses. (B) vAcE (baculovirus carrying a CMV promoter-driven EGFP) at an MOI of 20 was added with vAcIE2 (baculovirus carrying a CMV promoter-driven IE2) at an MOI of 0 or 20. A vAcE control at an MOI of 200 was also included as a comparison. Significant upregulation of the CMV promoter was seen with the addition of IE2 expressing baculovirus. Journal of Virology 83 (8) p. 3604-3616. Read more...