RESUMO
BACKGROUND: The proteasome is a multi-subunit complex and a major proteolytic machinery in cells. Most subunits are essential for proteasome function, and depletion of individual subunits normally results in lethality. RPN-12/Rpn12/PSMD8 is a lid subunit of the 19S regulatory particle (RP) of the 26S proteasome. Studies in Caenorhabditis elegans demonstrated that RNAi depletion of RPN-12 does not result in lethality. RPN-12 has not been well studied in higher eukaryotes. In this study, we investigate the biological significance of RPN-12 in C. elegans. RESULTS: We found that the null mutant rpn-12(av93) did not cause major impairment of the proteolytic activity of the proteasome. Most rpn-12(av93) hermaphrodites lack sperm leading to feminization of the germ line that can be partially rescued by mating to males. The lack of sperm phenotype can be suppressed by downregulation of TRA-1, a player in the hermaphrodite germline sex determination pathway. Also, rpn-12(av93) animals show significant nuclear accumulation of the meiotic kinase WEE-1.3, a protein predominantly localized to the perinuclear region. Interestingly, chemical inhibition of the proteasome did not cause nuclear accumulation of WEE-1.3. CONCLUSIONS: RPN-12 plays a previously unknown role in oogenesis and the germline sex determination pathway in C. elegans hermaphrodites.
Assuntos
Proteínas de Caenorhabditis elegans/fisiologia , Caenorhabditis elegans/fisiologia , Complexo de Endopeptidases do Proteassoma/fisiologia , Processos de Determinação Sexual , Animais , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ligação a DNA/metabolismo , Oócitos/fisiologia , Complexo de Endopeptidases do Proteassoma/genética , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Fatores de Transcrição/metabolismoRESUMO
Five subcluster C1 mycobacteriophages, Blackbrain, Cactojaque, Kboogie, Trinitium, and YoungMoneyMata, were isolated from soil using the host Mycobacterium smegmatis mc2155. The genome sizes range from 154,512 to 156,223 bp. The largest genome encodes 237 predicted proteins, 34 tRNAs, and 1 transfer-messenger RNA (tmRNA).
RESUMO
Four lytic mycobacteriophages, namely, SynergyX, Abinghost, Bananafish, and Delton, were isolated from soil in Washington, DC, using the bacterial host Mycobacterium smegmatis mc2155. Analysis of the genomes revealed that they belong to two subclusters of actinobacteriophage cluster B (subclusters B2 and B3) and subcluster D1 of cluster D.
RESUMO
We have generated a WEE-1.3 strain in C. elegans wherewe have endogenously tagged the C-terminus with GFP. In this publication we demonstrate that this new strain exhibits the same expression localization pattern as the WEE-1.3 antibody and N-terminally endogenously GFP-tagged WEE-1.3 strain that have been previously published. We also show for the first time that endogenously tagging WEE-1.3 at either termini does not affect the reproductive function of the worms.
RESUMO
The nematode C. elegans has a contingent of five sod genes, one of the largest among aerobic organisms. Earlier studies revealed each of the five sod genes is capable of making perfectly active SOD proteins in heterologous expression systems therefore none appears to be a pseudogene. Yet deletion of the entire contingent of sod genes fails to impose any effect on the survival of C. elegans except these animals appear more sensitive to extraneously applied oxidative stress conditions. We asked how many of the five sod genes are actually making active SOD enzymes in C. elegans through the usage of in-gel SOD activity analysis and by using KCN as a selective inhibitor against Cu-ZnSOD enzyme(s). Here we provide evidence that out of the five SOD proteins only the mitochondrial SOD is active in the water-soluble fraction of C. elegans extracts albeit at an apparently much lower activity than the multiple active SODs in D. melanogaster and E. coli. We had no opportunity to test the activity of Sod-4a isoform which is possibly a membrane-bound form of SOD. The mutant analysis further confirmed that among the two mitochondrial SOD proteins, SOD-2 is the only naturally active SOD in C. elegans.
Assuntos
Superóxido Dismutase/metabolismo , Animais , Caenorhabditis elegansRESUMO
Two temperate mycobacteriophages, Dallas and Jonghyun, were isolated from soil in Washington, DC, using the bacterial host Mycobacterium smegmatis mc2155. Analysis of the genomes revealed that Dallas and Jonghyun belong to clusters J and G, respectively. The structures of the genomes are typical of their respective clusters.