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During analysis of the proteome in the cerebrospinal fluid (CSF) of the Caucasian form of moyamoya disease (MMD), a novel post-translational modification of human transthyretin was observed. Two-dimensional electrophoresis and subsequent peptide sequencing with ESI-MS/MS were performed to discover the gamma-carboxylation of the Glu-42 (Gla-42).

The elaC gene of Escherichia coli encodes a binuclear zinc phosphodiesterase (ZiPD). ZiPD homologs from various species act as3' tRNA processing endoribonucleases, and although the homologous gene in Bacillus subtilis is essential for viability [EMBO J. 22(2003) 4534], the physiological function of E. coli ZiPD has remained enigmatic. In order to investigate the function of E. coli ZiPDwe generated and characterized an E. coli elaC deletion mutant. Surprisingly, the E. coli elaC deletion mutant was viable and had wild-type like growth properties. Microarray-based transcriptional analysis indicated expression of the E. coli elaC gene at basal levels during aerobic growth. The elaC gene deletion had no effect on the expression of genes coding for RNases or amino-acyl tRNA synthetases or any other gene among a total of > 1300 genes probed. 2D-PAGE analysis showed that the elaC mutation, like-wise, had no effect on the proteome. These results strengthen doubts about the involvement of E. coli ZiPD in tRNA maturation and suggest functional diversity within the ZiPD/ElaC1 protein family. In addition to these unexpected features of the E. coli elaC deletion mutant, a sequence comparison of ZiPD (ElaC1) proteins revealed specific regions for either enterobacterial or mammalian ZiPD (ElaC1) proteins.

Background and Aims Influenza viruses cause respiratory infection in humans and result in substantial illness, death, and economic burden. To date, however, the mechanisms by which these viruses cause disease are not fully understood. Methods To investigate the proteomic profile of children infected with seasonal influenza A virus, nasal aspirates derived from children ( n = 12) experiencing flu symptoms caused by seasonal influenza A virus were analyzed using two-dimensional electrophoresis (2-DE). Control nasal samples were taken from the same group of children 8–10 weeks later when they were symptom free. Results Analysis of the 2-DE gels revealed eight spots differentially expressed, which were further analyzed using mass spectrometry. Ten proteins were found to be differentially upregulated in the infected children including PLUNC, cystatin S, cystatin SA, S100A9, lipocalin 1 fragments ( n = 2), truncated lactotransferrin, two immunoglobulin (Ig) kappa fragments and one immunoglobulin (Ig) lambda fragment. Conclusions Our findings reveal that the composition of nasal secretions in influenza virus respiratory infections is different from that when children are healthy and may provide further insights into the pathogenesis of respiratory infections caused by seasonal influenza A viruses.

During analysis of the proteome in the cerebrospinal fluid (CSF) of the Caucasian form of moyamoya disease (MMD), a novel post-translational modification of human transthyretin was observed. Two-dimensional electrophoresis and subsequent peptide sequencing with ESI-MS/MS were performed to discover the gamma-carboxylation of the Glu-42 (Gla-42).

In extracts of the unicellular cyanobacterium Gloeothece, the Fe-protein of nitrogenase can be separated by SDS–PAGE into two antigenically identifiable components. Unlike the situation in photosynthetic bacteria such as Rhodospirillum rubrum, these two forms do not arise from covalent modification of the protein by ADP-ribosylation. Rather, the Fe-protein of Gloeothece nitrogenase is subjected to modification by palmitoylation.