• MeSH
• posttranslační úpravy proteinů MeSH
• proteomika metody   MeSH
• Publikační typ
• monografie MeSH

• Konspekt
• Biologické vědy
• NLK Obory
• chemie, klinická chemie
• biologie

Vitamin D receptor (VDR) is a member of the nuclear receptor (NR) superfamily of ligand-activated transcription factors. Activated VDR is responsible for maintaining calcium and phosphate homeostasis, and is required for proper cellular growth, cell differentiation and apoptosis. The expression of both phases I and II drug-metabolizing enzymes is also regulated by VDR, therefore it is clinically important.Post-translational modifications of NRs have been known as an important mechanism modulating the activity of NRs and their ability to drive the expression of target genes. The aim of this mini review is to summarize the current knowledge about post-transcriptional and post-translational modifications of VDR.

• MeSH
• fosforylace MeSH
• genetická transkripce MeSH
• lidé MeSH
• mikro RNA genetika   MeSH
• posttranslační úpravy proteinů * MeSH
• receptory kalcitriolu genetika   metabolismus   MeSH
• regulace genové exprese MeSH
• sumoylace MeSH
• ubikvitinace MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Pregnane X receptor (PXR) is a member of the nuclear receptor (NR) superfamily of ligand-activated transcription factors and is activated by a huge variety of endobiotics and xenobiotics, including many clinical drugs. PXR plays key roles not only as a xenosensor in the regulation of both major phase I and II drug metabolism and transporters but also as a physiological sensor in the modulation of bile acid and cholesterol metabolism, glucose and lipid metabolism, and bone and endocrine homeostasis. Post-translational modifications such as phosphorylation have been shown to modulate the activity of many NRs, including PXR, and constitute an important mechanism for crosstalk between signaling pathways and regulation of genes involved in both xenobiotic and endobiotic metabolism. In addition, microRNAs have recently been shown to constitute another level of PXR activity regulation. The objective of this review is to comprehensively summarize current understanding of post-transcriptional and post-translational modifications of PXR in regulation of xenobiotic-metabolizing cytochrome P450 (CYP) genes, mainly in hepatic tissue. We also discuss the importance of PXR in crosstalk with cell signaling pathways, which at the level of transcription modify expression of genes associated with some physiological and pathological stages in the organs. Finally, we indicate that these PXR modifications may have important impacts on CYP-mediated biotransformation of some clinically used drugs.

• MeSH
• biotransformace MeSH
• enzymová indukce účinky léků   MeSH
• interakční proteinové domény a motivy MeSH
• játra účinky léků   enzymologie   metabolismus   MeSH
• lidé MeSH
• messenger RNA metabolismus   MeSH
• posttranskripční úpravy RNA * účinky léků   MeSH
• posttranslační úpravy proteinů * účinky léků   MeSH
• steroidní receptory chemie   genetika   metabolismus   MeSH
• systém (enzymů) cytochromů P-450 genetika   metabolismus   MeSH
• xenobiotika metabolismus   farmakokinetika   toxicita   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Collagen is the most abundant protein in the animal and human bodies, and it is not exempt from this aging phenomenon. Some age-related changes may appear on collagen sequences, such as increased surface hydrophobicity, the appearance of post-translational modifications, and amino acids racemization. This study has shown that the protein hydrolysis under deuterium conditions is privileged to limit the natural racemization during the hydrolysis. Indeed, under the deuterium condition, the homochirality of recent collagens is preserved whose amino acids are found in their L-form. However, in aging collagen, a natural amino acid racemization was observed. These results confirmed that the % d-amino acids are progressive according to age. The collagen sequence is degraded over time, and a fifth of the sequence information is lost during aging. Post-translational modifications (PTMs) in aging collagens can be a hypothesis to explain the modification of the hydrophobicity of the protein with the decrease of hydrophilic groups and the increase of hydrophobic groups. Finally, the exact positions of d-amino acids and PTMs have been correlated and elucidated.

• MeSH
• aminokyseliny * chemie   MeSH
• chromatografie kapalinová MeSH
• deuterium chemie   MeSH
• kolagen MeSH
• lidé MeSH
• posttranslační úpravy proteinů MeSH
• proteomika * MeSH
• stárnutí MeSH
• tandemová hmotnostní spektrometrie metody   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Bisphenol S (BPS) is increasingly used as a replacement for bisphenol A in the manufacture of products containing polycarbonates and epoxy resins. However, further studies of BPS exposure are needed for the assessment of health risks to humans. In this study we assessed the potential harmfulness of low-dose BPS on reproduction in male mice. METHODS: To simulate human exposure under experimental conditions, 8-week-old outbred ICR male mice received 8 weeks of drinking water containing a broad range of BPS doses [0.001, 1.0, or 100 μg/kg body weight (bw)/day, BPS1-3] or vehicle control. Mice were sacrificed and testicular tissue taken for histological analysis and protein identification by nano-liquid chromatography/mass spectrometry (MS) and sperm collected for immunodetection of acetylated lysine and phosphorylated tyrosine followed by protein characterisation using matrix-assisted laser desorption ionisation time-of-flight MS (MALDI-TOF MS). RESULTS: The results indicate that compared to vehicle, 100 μg/kg/day exposure (BPS3) leads to 1) significant histopathology in testicular tissue; and, 2) higher levels of the histone protein γH2AX, a reliable marker of DNA damage. There were fewer mature spermatozoa in the germ layer in the experimental group treated with 1 μg/kg bw (BPS2). Finally, western blot and MALDI-TOF MS studies showed significant alterations in the sperm acetylome and phosphorylome in mice treated with the lowest exposure (0.001 μg/kg/day; BPS1), although the dose is several times lower than what has been published so far. CONCLUSIONS: In summary, this range of qualitative and quantitative findings in young male mice raise the possibility that very low doses of BPS may impair mammalian reproduction through epigenetic modifications of sperm proteins.

• MeSH
• acetylace účinky léků   MeSH
• endokrinní disruptory farmakologie   MeSH
• epigeneze genetická MeSH
• fenoly farmakologie   MeSH
• fosforylace účinky léků   MeSH
• myši MeSH
• poškození DNA účinky léků   MeSH
• posttranslační úpravy proteinů účinky léků   MeSH
• spermie účinky léků   MeSH
• sulfony farmakologie   MeSH
• testis účinky léků   patologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• zrání spermie účinky léků   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Nitric oxide (NO) is considered as a signalling molecule involved in a variety of important physiological and pathological processes in plant and animal systems. The major pathway of NO reactions in vivo represents S-nitrosation of thiols to form S-nitrosothiols. S-nitrosoglutathione reductase (GSNOR) is the key enzyme in the degradation pathway of S-nitrosoglutathione (GSNO), a low-molecular weight adduct of NO and glutathione. GSNOR indirectly regulates the level of protein S-nitrosothiol in the cells. This study was focused on the dynamic regulation of the activity of plant GSNORs through reversible S-nitrosation and/or oxidative modifications of target cysteine residues. Pre-incubation with NO/NO- donors or hydrogen peroxide resulted in a decreased reductase and dehydrogenase activity of all studied plant GSNORs. Incubation with thiol reducing agent completely reversed inhibitory effects of nitrosative modifications and partially also oxidative inhibition. In biotin-labelled samples, S-nitrosation of plant GSNORs was confirmed after immunodetection and using mass spectrometry S-nitrosation of conserved Cys271 was identified in tomato GSNOR. Negative regulation of constitutive GSNOR activity in vivo by nitrosative or oxidative modifications might present an important mechanism to control GSNO levels, a critical mediator of the downstream signalling effects of NO, as well as for formaldehyde detoxification in dehydrogenase reaction mode.

• MeSH
• aldehydoxidoreduktasy antagonisté a inhibitory   chemie   metabolismus   MeSH
• cystein chemie   metabolismus   MeSH
• donory oxidu dusnatého farmakologie   MeSH
• nitrosace MeSH
• oxid dusnatý metabolismus   MeSH
• oxidace-redukce MeSH
• peroxid vodíku farmakologie   MeSH
• posttranslační úpravy proteinů MeSH
• rekombinantní proteiny chemie   genetika   metabolismus   MeSH
• rostlinné proteiny antagonisté a inhibitory   chemie   metabolismus   MeSH
• S-nitrosoglutathion metabolismus   MeSH
• S-nitrosothioly metabolismus   MeSH
• signální transdukce MeSH
• Solanum lycopersicum genetika   růst a vývoj   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

AIM: In this study, we analysed the post-translational modification of receptor tyrosine kinase-like orphan receptor (Ror1). Ror1 is highly upregulated in B cells of patients with chronic lymphocytic leukaemia (CLL). Molecularly, Ror1 acts as the Wnt receptor in the non-canonical Wnt pathway. METHODS: The level of Ror1 glycosylation in HEK293 cells and in primary human CLL cells was analysed by treatment of inhibitors interfering with different steps of glycosylation process and by direct treatment of cell lysates with N-glycosidase. Ror1 ubiquitination was determined by ubiquitination assay. Functional consequences of post-translational modifications were analysed by immunohistochemistry and by analysis of cell surface proteins. Differences in Ror1 glycosylation were confirmed by analysis of 14 samples of B cells from CLL patients. RESULTS: We demonstrate that Ror1 is extensively modified by N-linked glycosylation. Glycosylation produces several variants of Ror1 with electrophoretic migration of approx. 100, 115 and 130 kDa. Inhibition of glycosylation interferes with cell surface localization of the 130-kDa variant of Ror1 and prevents Ror1-induced formation of filopodia. Moreover, we show that 130-kDa Ror1 is mono-ubiquitinated. Furthermore, individual CLL patients show striking differences in the electrophoretic migration of Ror1, which correspond to the level of glycosylation. CONCLUSION: Our data show that Ror1 undergoes complex post-translational modifications by glycosylation and mono-ubiquitination. These modifications regulate Ror1 localization and signalling, and are highly variable among individual CLL patients. These may suggest that Ror1 signals only in a subset of CLL patients despite Ror1 levels are ubiquitously high in all CLL patients.

• MeSH
• B-lymfocyty metabolismus   MeSH
• CHO buňky MeSH
• chronická lymfatická leukemie metabolismus   MeSH
• Cricetulus MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• glykosylace MeSH
• HEK293 buňky MeSH
• imunohistochemie MeSH
• konfokální mikroskopie MeSH
• křečci praví MeSH
• lidé MeSH
• molekulová hmotnost MeSH
• posttranslační úpravy proteinů účinky léků   MeSH
• průtoková cytometrie MeSH
• pseudopodia metabolismus   MeSH
• signální transdukce účinky léků   MeSH
• sirotčí receptory podobné receptoru tyrosinkinasy chemie   genetika   metabolismus   MeSH
• transfekce MeSH
• transport proteinů MeSH
• ubikvitinace MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• lidé MeSH
• zvířata 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.

• MeSH
• endoplazmatické retikulum metabolismus   MeSH
• intracelulární membrány metabolismus   MeSH
• malá interferující RNA MeSH
• posttranslační úpravy proteinů genetika   fyziologie   MeSH
• transport proteinů fyziologie   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem 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

• MeSH
• molekulární biologie MeSH
• proteiny MeSH
• referenční knihy MeSH
• Publikační typ
• příručky MeSH

• Konspekt
• Biochemie. Molekulární biologie. Biofyzika
• NLK Obory
• biologie
• biochemie