Aging is the most critical factor that influences the quality of post-ovulatory oocytes. Age-related molecular pathways remain poorly understood in fish oocytes. In this study, we examined the effect of oocyte aging on specific histone acetylation in common carp Cyprinus carpio. The capacity to progress to the larval stage in oocytes that were aged for 28 h in vivo and in vitro was evaluated. Global histone modifications and specific histone acetylation (H3K9ac, H3K14ac, H4K5ac, H4K8ac, H4K12ac, and H4K16ac) were investigated during oocyte aging. Furthermore, the activity of histone acetyltransferase (HAT) was assessed in fresh and aged oocytes. Global histone modifications did not exhibit significant alterations during 8 h of oocyte aging. Among the selected modifications, H4K12ac increased significantly at 28 h post-stripping (HPS). Although not significantly different, HAT activity exhibited an upward trend during oocyte aging. Results of our current study indicate that aging of common carp oocytes for 12 h results in complete loss of egg viability rates without any consequence in global and specific histone modifications. However, aging oocytes for 28 h led to increased H4K12ac. Thus, histone acetylation modification as a crucial epigenetic mediator may be associated with age-related defects, particularly in oocytes of a more advanced age.
The p53 and Mouse double minute 2 (MDM2) proteins are hubs in extensive networks of interactions with multiple partners and functions. Intrinsically disordered regions help to adopt function-specific structural conformations in response to ligand binding and post-translational modifications. Different techniques have been used to dissect interactions of the p53-MDM2 pathway, in vitro, in vivo, and in situ each having its own advantages and disadvantages. This review uses the p53-MDM2 to show how different techniques can be employed, illustrating how a combination of in vitro and in vivo techniques is highly recommended to study the spatio-temporal location and dynamics of interactions, and to address their regulation mechanisms and functions. By using well-established techniques in combination with more recent advances, it is possible to rapidly decipher complex mechanisms, such as the p53 regulatory pathway, and to demonstrate how protein and nucleotide ligands in combination with post-translational modifications, result in inter-allosteric and intra-allosteric interactions that govern the activity of the protein complexes and their specific roles in oncogenesis. This promotes elegant therapeutic strategies that exploit protein dynamics to target specific interactions.
- MeSH
- fosforylace genetika MeSH
- jaderné proteiny MeSH
- lidé MeSH
- myši MeSH
- nádorový supresorový protein p53 genetika MeSH
- poškození DNA genetika MeSH
- posttranslační úpravy proteinů genetika MeSH
- proteiny buněčného cyklu genetika MeSH
- protoonkogenní proteiny c-mdm2 genetika MeSH
- vazba proteinů genetika MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Hepatitis B virus (HBV) core protein (HBc) plays many roles in the HBV life cycle, such as regulation of transcription, RNA encapsidation, reverse transcription, and viral release. To accomplish these functions, HBc interacts with many host proteins and undergoes different post-translational modifications (PTMs). One of the most common PTMs is ubiquitination, which was shown to change the function, stability, and intracellular localization of different viral proteins, but the role of HBc ubiquitination in the HBV life cycle remains unknown. Here, we found that HBc protein is post-translationally modified through K29-linked ubiquitination. We performed a series of co-immunoprecipitation experiments with wild-type HBc, lysine to arginine HBc mutants and wild-type ubiquitin, single lysine to arginine ubiquitin mutants, or single ubiquitin-accepting lysine constructs. We observed that HBc protein could be modified by ubiquitination in transfected as well as infected hepatoma cells. In addition, ubiquitination predominantly occurred on HBc lysine 7 and the preferred ubiquitin chain linkage was through ubiquitin-K29. Mass spectrometry (MS) analyses detected ubiquitin protein ligase E3 component N-recognin 5 (UBR5) as a potential E3 ubiquitin ligase involved in K29-linked ubiquitination. These findings emphasize that ubiquitination of HBc may play an important role in HBV life cycle.
- MeSH
- arginin genetika MeSH
- buněčné linie MeSH
- buňky Hep G2 MeSH
- HEK293 buňky MeSH
- hepatitida B genetika MeSH
- hepatocelulární karcinom genetika MeSH
- lidé MeSH
- lysin genetika MeSH
- nádorové buněčné linie MeSH
- posttranslační úpravy proteinů genetika MeSH
- ubikvitin genetika MeSH
- ubikvitinace genetika MeSH
- ubikvitinligasy genetika MeSH
- virové proteiny genetika MeSH
- virus hepatitidy B genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- MeSH
- exprese genu genetika MeSH
- karcinogeneze genetika imunologie účinky léků MeSH
- lidé MeSH
- posttranslační úpravy proteinů genetika imunologie účinky léků MeSH
- proliferace buněk genetika účinky léků MeSH
- sumoylace genetika imunologie MeSH
- ubikvitinace * genetika imunologie účinky léků MeSH
- Check Tag
- lidé MeSH
We examined the levels and distribution of post-translationally modified histones and protamines in human sperm. Using western blot immunoassay, immunofluorescence, mass spectrometry (MS), and FLIM-FRET approaches, we analyzed the status of histone modifications and the protamine P2. Among individual samples, we observed variability in the levels of H3K9me1, H3K9me2, H3K27me3, H3K36me3, and H3K79me1, but the level of acetylated (ac) histones H4 was relatively stable in the sperm head fractions, as demonstrated by western blot analysis. Sperm heads with lower levels of P2 exhibited lower levels of H3K9ac, H3K9me1, H3K27me3, H3K36me3, and H3K79me1. A very strong correlation was observed between the levels of P2 and H3K9me2. FLIM-FRET analysis additionally revealed that acetylated histones H4 are not only parts of sperm chromatin but also appear in a non-integrated form. Intriguingly, H4ac and H3K27me3 were detected in sperm tail fractions via western blot analysis. An appearance of specific histone H3 and H4 acetylation and H3 methylation in sperm tail fractions was also confirmed by both LC-MS/MS and MALDI-TOF MS analysis. Taken together, these data indicate that particular post-translational modifications of histones are uniquely distributed in human sperm, and this distribution varies among individuals and among the sperm of a single individual.
- MeSH
- acetylace MeSH
- chromatin genetika MeSH
- histonlysin-N-methyltransferasa biosyntéza genetika MeSH
- histony genetika metabolismus MeSH
- lidé MeSH
- metylace MeSH
- posttranslační úpravy proteinů genetika MeSH
- sekvence aminokyselin MeSH
- spermie růst a vývoj metabolismus MeSH
- tandemová hmotnostní spektrometrie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The metazoan Sec61 translocon transports polypeptides into and across the membrane of the endoplasmic reticulum via two major routes, a well-established co-translational pathway and a post-translational alternative. We have used two model substrates to explore the elements of a secretory protein precursor that preferentially direct it towards a co- or post-translational pathway for ER translocation. Having first determined the capacity of precursors to enter ER derived microsomes post-translationally, we then exploited semi-permeabilized mammalian cells specifically depleted of key membrane components using siRNA to address their contribution to the membrane translocation process. These studies suggest precursor chain length is a key factor in the post-translational translocation at the mammalian ER, and identify Sec62 and Sec63 as important components acting on this route. This role for Sec62 and Sec63 is independent of the signal sequence that delivers the precursor to the ER. However, the signal sequence can influence the subsequent membrane translocation process, conferring sensitivity to a small molecule inhibitor and dictating reliance on the molecular chaperone BiP. Our data support a model where secretory protein precursors that fail to engage the signal recognition particle, for example because they are short, are delivered to the ER membrane via a distinct route that is dependent upon both Sec62 and Sec63. Although this requirement for Sec62 and Sec63 is unaffected by the specific signal sequence that delivers a precursor to the ER, this region can influence subsequent events, including both Sec61 mediated transport and the importance of BiP for membrane translocation. Taken together, our data suggest that an ER signal sequence can regulate specific aspects of Sec61 mediated membrane translocation at a stage following Sec62/Sec63 dependent ER delivery.
Glukokortikoidy jsou protizánětlivá léčiva, která ovlivňují expresi genů, transkripci v jádře, posttranskripční a posttranslační mechanismy v cytoplazmě. Aktivita prozánětlivých proteinů je regulována i posttranskripčními mechanismy, které ovlivňují stabilitu mRNA. Pochopení nových signálních drah regulujících protizánětlivou aktivitu glukokortikoidů je cestou k dosažení maximální léčebné odpovědi v organismu.
Glucocorticoids are anti-inflammatory drugs that regulate gene expression, nuclear transcription and post-transcriptional and post-translational mechanisms in the cytoplasm. The activity of the anti-inflammatory proteins is also regulated by the post-transcriptional mechanisms that control mRNA stability. Understanding new signalling pathways involved in the regulation of anti-inflammatory activity of glucocorticoids is prerequisite for achieving the best possible therapeutic response.
- MeSH
- glukokortikoidy farmakokinetika farmakologie MeSH
- histony imunologie metabolismus účinky léků MeSH
- posttranskripční úpravy RNA genetika imunologie účinky léků MeSH
- posttranslační úpravy proteinů genetika účinky léků MeSH
- regulace genové exprese genetika imunologie účinky léků MeSH
- zánět farmakoterapie genetika imunologie MeSH
Mitochondrial processing peptidases are heterodimeric enzymes (alpha/betaMPP) that play an essential role in mitochondrial biogenesis by recognizing and cleaving the targeting presequences of nuclear-encoded mitochondrial proteins. The two subunits are paralogues that probably evolved by duplication of a gene for a monomeric metallopeptidase from the endosymbiotic ancestor of mitochondria. Here, we characterize the MPP-like proteins from two important human parasites that contain highly reduced versions of mitochondria, the mitosomes of Giardia intestinalis and the hydrogenosomes of Trichomonas vaginalis. Our biochemical characterization of recombinant proteins showed that, contrary to a recent report, the Trichomonas processing peptidase functions efficiently as an alpha/beta heterodimer. By contrast, and so far uniquely among eukaryotes, the Giardia processing peptidase functions as a monomer comprising a single betaMPP-like catalytic subunit. The structure and surface charge distribution of the Giardia processing peptidase predicted from a 3-D protein model appear to have co-evolved with the properties of Giardia mitosomal targeting sequences, which, unlike classic mitochondrial targeting signals, are typically short and impoverished in positively charged residues. The majority of hydrogenosomal presequences resemble those of mitosomes, but longer, positively charged mitochondrial-type presequences were also identified, consistent with the retention of the Trichomonas alphaMPP-like subunit. Our computational and experimental/functional analyses reveal that the divergent processing peptidases of Giardia mitosomes and Trichomonas hydrogenosomes evolved from the same ancestral heterodimeric alpha/betaMPP metallopeptidase as did the classic mitochondrial enzyme. The unique monomeric structure of the Giardia enzyme, and the co-evolving properties of the Giardia enzyme and substrate, provide a compelling example of the power of reductive evolution to shape parasite biology.
- MeSH
- down regulace genetika MeSH
- fylogeneze MeSH
- genová dávka MeSH
- Giardia lamblia genetika metabolismus ultrastruktura MeSH
- glycin fyziologie genetika chemie MeSH
- metaloendopeptidasy genetika chemie metabolismus MeSH
- mitochondrie metabolismus MeSH
- multimerizace proteinu MeSH
- organely metabolismus MeSH
- podjednotky proteinů genetika MeSH
- posttranslační úpravy proteinů genetika MeSH
- proteinové domény bohaté na prolin fyziologie genetika MeSH
- řízená evoluce molekul MeSH
- sekvence aminokyselin MeSH
- transport proteinů MeSH
- Trichomonas vaginalis genetika metabolismus ultrastruktura MeSH
- vodík metabolismus MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
- Publikační typ
- práce podpořená grantem MeSH
- srovnávací studie MeSH
