The transcription factor c-Myc, a key regulator of cellular processes, has long been associated with roles in cell proliferation and apoptosis. This review analyses the multiple functions of c-Myc by examining the different c-Myc isoforms in detail. The impact of different c-Myc isoforms, in particular p64 and p67, on fundamental biological processes remains controversial. It is necessary to investigate the different isoforms in the context of proto-oncogenesis. The current knowledge base suggests that neoplastic lesions may possess the means for self-destruction via increased c-Myc activity. This review presents the most relevant information on the c-Myc locus and focuses on a number of isoforms, including p64 and p67. This compilation provides a basis for the development of therapeutic approaches that target the potent growth arresting and pro-apoptotic functions of c-Myc. This information can then be used to develop targeted interventions against specific isoforms with the aim of shifting the oncogenic effects of c-Myc from pro-proliferative to pro-apoptotic. The research summarised in this review can deepen our understanding of how c-Myc activity contributes to different cellular responses, which will be crucial in developing effective therapeutic strategies; for example, isoform-specific approaches may allow for precise modulation of c-Myc function.

• Klíčová slova
• MycHex1, c-Myc S, c-Myc locus structure, mrtl, p64 isoform, p67 isoform,
• MeSH
• apoptóza MeSH
• messenger RNA MeSH
• proliferace buněk MeSH
• protein - isoformy genetika   MeSH
• protoonkogenní proteiny c-myc * genetika   MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• messenger RNA MeSH
• protein - isoformy MeSH
• protoonkogenní proteiny c-myc * MeSH

Casein kinases 1 (CK1) are key signaling molecules that have emerged recently as attractive therapeutic targets in particular for the treatment of hematological malignancies. Herein, we report the identification of a new class of potent and highly selective inhibitors of CK1α, δ and ϵ. Based on their optimal in vitro and in vivo profiles and their exclusive selectivity, MU1250, MU1500 and MU1742 were selected as quality chemical probes for those CK1 isoforms. At proper concentrations, MU1250 and MU1500 allow for specific targeting of CK1δ or dual inhibition of CK1δ/ϵ in cells. The compound MU1742 also efficiently inhibits CK1α and, to our knowledge, represents the first potent and highly selective inhibitor of this enzyme. In addition, we demonstrate that the central 1H-pyrrolo[2,3-b]pyridine-imidazole pharmacophore can be used as the basis of highly selective inhibitors of other therapeutically relevant protein kinases, e.g. p38α, as exemplified by the compound MU1299.

• Klíčová slova
• CK1, Chemical Probe, Inhibitor, Isoform Selectivity, Wnt Pathway,
• MeSH
• inhibitory proteinkinas chemie   MeSH
• kaseinkinasa I * metabolismus   MeSH
• lidé MeSH
• protein - isoformy metabolismus   MeSH
• signální transdukce * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• inhibitory proteinkinas MeSH
• kaseinkinasa I * MeSH
• protein - isoformy MeSH

The pathogenic molecular mechanisms underlying the insurgence of nasal polyps has not been completely defined. In some patients, these lesions can have a recurrence after surgery removal, and the difference between recurrent and not recurrent patients is still unclear. To molecularly characterize and distinguish between these two classes, a cohort of patients affected by nasal polyposis was analysed. In all patients we analysed the p63 isoform expression using fresh tissues taken after surgery. Moreover, confocal immunofluorescence analysis of fixed sections was performed. The results show high ΔNp63 expression in samples from the nasal polyps of patients compared to the normal epithelia. Analysis of the expression level of the TAp63 isoform shows differential expression between the patients with recurrence compared to those not recurring. The data, considered as the ΔN/TAp63 ratio, really discriminate the two groups. In fact, even though ΔNp63 is expressed in non-recurrent patients, the resulting ratio ΔN/TAp63 is significantly lower in these patients. This clearly indicates that the status of TAp63 expression, represented by the ΔN/TAp63 ratio, could be considered a prognostic marker of low recurrence probability. In these samples we also investigated the expression of OTX2 transcription factor, known to be a selective activator of TAp63, detecting a significant correlation. Database analysis of HNSCC patients showed increased survival for the patients presenting OTX2 amplification and/or overexpression. These results, together with the fact that TAp63 can be selectively upregulated by HDAC inhibitors, open the possibility to consider local treatment of recurrent nasal polyps with these molecules.

• MeSH
• fluorescenční protilátková technika MeSH
• lidé MeSH
• nádorové supresorové proteiny genetika   metabolismus   MeSH
• nosní polypy genetika   metabolismus   MeSH
• protein - isoformy genetika   metabolismus   MeSH
• regulace genové exprese u nádorů MeSH
• transkripční faktory Otx genetika   metabolismus   MeSH
• transkripční faktory genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• nádorové supresorové proteiny MeSH
• OTX2 protein, human MeSH Prohlížeč
• protein - isoformy MeSH
• TP63 protein, human MeSH Prohlížeč
• transkripční faktory Otx MeSH
• transkripční faktory MeSH

Cytochrome c oxidase (COX) is regulated through tissue-, development- or environment-controlled expression of subunit isoforms. The COX4 subunit is thought to optimize respiratory chain function according to oxygen-controlled expression of its isoforms COX4i1 and COX4i2. However, biochemical mechanisms of regulation by the two variants are only partly understood. We created an HEK293-based knock-out cellular model devoid of both isoforms (COX4i1/2 KO). Subsequent knock-in of COX4i1 or COX4i2 generated cells with exclusive expression of respective isoform. Both isoforms complemented the respiratory defect of COX4i1/2 KO. The content, composition, and incorporation of COX into supercomplexes were comparable in COX4i1- and COX4i2-expressing cells. Also, COX activity, cytochrome c affinity, and respiratory rates were undistinguishable in cells expressing either isoform. Analysis of energy metabolism and the redox state in intact cells uncovered modestly increased preference for mitochondrial ATP production, consistent with the increased NADH pool oxidation and lower ROS in COX4i2-expressing cells in normoxia. Most remarkable changes were uncovered in COX oxygen kinetics. The p50 (partial pressure of oxygen at half-maximal respiration) was increased twofold in COX4i2 versus COX4i1 cells, indicating decreased oxygen affinity of the COX4i2-containing enzyme. Our finding supports the key role of the COX4i2-containing enzyme in hypoxia-sensing pathways of energy metabolism.

• Klíčová slova
• mitochondria, OXPHOS, respiratory chain, cytochrome c oxidase, COX, COX4 isoforms, COX4i2, oxygen affinity, p50, oxygen sensing,
• MeSH
• cytochromy c metabolismus   MeSH
• HEK293 buňky MeSH
• kyslík metabolismus   MeSH
• lidé MeSH
• protein - isoformy metabolismus   MeSH
• regulace genové exprese enzymů fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• cytochromy c MeSH
• kyslík MeSH
• protein - isoformy MeSH

Profiling of biological relationships between different molecular layers dissects regulatory mechanisms that ultimately determine cellular function. To thoroughly assess the role of protein post-translational turnover, we devised a strategy combining pulse stable isotope-labeled amino acids in cells (pSILAC), data-independent acquisition mass spectrometry (DIA-MS), and a novel data analysis framework that resolves protein degradation rate on the level of mRNA alternative splicing isoforms and isoform groups. We demonstrated our approach by the genome-wide correlation analysis between mRNA amounts and protein degradation across different strains of HeLa cells that harbor a high grade of gene dosage variation. The dataset revealed that specific biological processes, cellular organelles, spatial compartments of organelles, and individual protein isoforms of the same genes could have distinctive degradation rate. The protein degradation diversity thus dissects the corresponding buffering or concerting protein turnover control across cancer cell lines. The data further indicate that specific mRNA splicing events such as intron retention significantly impact the protein abundance levels. Our findings support the tight association between transcriptome variability and proteostasis and provide a methodological foundation for studying functional protein degradation.

• Klíčová slova
• DIA mass spectrometry, alternative splicing, protein turnover, proteomics, pulsed SILAC,
• MeSH
• alternativní sestřih MeSH
• HeLa buňky MeSH
• hmotnostní spektrometrie MeSH
• izoformy RNA genetika   metabolismus   MeSH
• izotopové značení metody   MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• protein - isoformy analýza   metabolismus   MeSH
• proteiny analýza   metabolismus   MeSH
• proteolýza MeSH
• proteomika metody   MeSH
• průběh práce MeSH
• regulace genové exprese u nádorů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• izoformy RNA MeSH
• messenger RNA MeSH
• protein - isoformy MeSH
• proteiny MeSH

A small library of boron-cluster- and metallacarborane-cluster-based ligands was designed, prepared, and tested for isoform-selective activation or inhibition of the three nitric oxide synthase isoforms. On the basis of the concept of creating a hydrophobic analogue of a natural substrate, a stable and nontoxic basic boron cluster system, previously used for boron neutron capture therapy, was modified by the addition of positively charged moieties to its periphery, providing hydrophobic and nonclassical hydrogen bonding interactions with the protein. Several of these compounds show efficacy for inhibition of NO synthesis with differential effects on the various nitric oxide synthase isoforms.

• MeSH
• chemické modely MeSH
• kobalt chemie   MeSH
• lidé MeSH
• molekulární struktura MeSH
• organokovové sloučeniny chemická syntéza   farmakologie   MeSH
• protein - isoformy MeSH
• sloučeniny boru chemická syntéza   farmakologie   MeSH
• synthasa oxidu dusnatého antagonisté a inhibitory   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• kobalt MeSH
• organokovové sloučeniny MeSH
• protein - isoformy MeSH
• sloučeniny boru MeSH
• synthasa oxidu dusnatého MeSH

The proteins of 14-3-3 family are substantially involved in the regulation of many biological processes including the apoptosis. We studied the changes in the expression of five 14-3-3 isoforms (beta, gamma, epsilon, tau, and zeta) during the apoptosis of JURL-MK1 and K562 cells. The expression level of all these proteins markedly decreased in relation with the apoptosis progression and all isoforms underwent truncation, which probably corresponds to the removal of several C-terminal amino acids. The observed 14-3-3 modifications were partially blocked by caspase-3 inhibition. In addition to caspases, a non-caspase protease is likely to contribute to 14-3-3's cleavage in an isoform-specific manner. While 14-3-3 gamma seems to be cleaved mainly by caspase-3, the alternative mechanism is essentially involved in the case of 14-3-3 tau, and a combined effect was observed for the isoforms epsilon, beta, and zeta. We suggest that the processing of 14-3-3 proteins could form an integral part of the programmed cell death or at least of some apoptotic pathways.

• MeSH
• apoptóza * MeSH
• buňky K562 MeSH
• hydrolýza MeSH
• kaspasa 3 MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• proteasy metabolismus   MeSH
• protein - isoformy metabolismus   MeSH
• proteiny 14-3-3 metabolismus   MeSH
• regulace genové exprese MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• kaspasa 3 MeSH
• proteasy MeSH
• protein - isoformy MeSH
• proteiny 14-3-3 MeSH

Acipenser sinensis and Acipenser dabryanus are critically endangered species, so germplasm conservation via cryopreservation of sperm is necessary. Disaccharides can act as membrane-impermeable cryoprotectants, and enolase3 (ENO3) and plasma membrane Ca2+ ATPase isoform (PMCA2) are proteins associated with sperm quality. We considered seven characteristics of sperm quality in cultured brood stock from A. sinensis and A. dabryanus. We tested use of sucrose or trehalose alone and in combination at different concentrations for cryopreservation of A. dabryanus sperm. A low concentration of sucrose plus trehalose (S15 T15 ) was optimal. Mixing of the extender with sucrose, lactose, or trehalose alone or with pairwise mixtures revealed that a mixture of lactose and trehalose (L15 T15 ) gave the best results for both A. sinensis and A. dabryanus. Enolase3 and PMCA2 expression levels were measured in cryopreserved A. sinensis sperm via Western blotting. Relative ENO3 and PMCA2 expression levels were examined, and the relationship between disaccharide composition, sperm quality and protein expression was explored in A. sinensis. The results showed that relative ENO3 and PMCA2 expression levels were the highest at L15 T15 in cryopreserved A. sinensis sperm. There were significant positive correlations between ENO3 expression and percentage membrane integrity, and between PMCA2 expression and sperm motility parameters (percentage of motile sperm, curvilinear velocity, straight-line velocity and average path velocity; p < .05) in cryopreserved A. sinensis sperm. Our results indicate the optimal disaccharide combination and concentrations for cryopreservation of A. sinensis and A. dabryanus sperm and suggest that ENO3 and PMCA2 expression levels could serve as a valuable indicator of sperm quality in A. sinensis.

• Klíčová slova
• cryopreservation, disaccharides, enolase3, plasma membrane Ca2+-ATPase isoform, sperm,
• MeSH
• buněčná membrána enzymologie   MeSH
• Ca2+-ATPasy účinky léků   MeSH
• disacharidy MeSH
• fosfopyruváthydratasa účinky léků   MeSH
• kryoprezervace veterinární   MeSH
• kryoprotektivní látky MeSH
• ohrožené druhy MeSH
• protein - isoformy MeSH
• ryby * MeSH
• uchování spermatu veterinární   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• Ca2+-ATPasy MeSH
• disacharidy MeSH
• fosfopyruváthydratasa MeSH
• kryoprotektivní látky MeSH
• protein - isoformy MeSH

The purpose of the present study was to compare the myosin heavy chain (MHC) isoform composition of the deltoid and vastus lateralis muscles of the dominant and non-dominant limbs in handball players. Eleven male Greek elite handball players (age 22.6 ± 1.9 yrs, training experience 10.6 ± 2.1 yrs, height 184.1 ± 4.1 cm, and weight 81.0 ± 12.5 kg) participated in the study. Four muscle biopsies were obtained from the dominant and non-dominant deltoid and vastus lateralis muscles during the in-season period. The MHC composition was determined using SDS-PAGE. No significant difference was found between the dominant and non-dominant muscles; Deltoid muscle: MHC I [(95%CI = -1.22, 0.33), P = 0.228], MHC ΙΙa [(95%CI = -0.32, 1.59), P = 0.168] and MHC IIx [(95%CI = -1.49, 1.10), P = 0.749]; Vastus lateralis muscle: MHC I [(95%CI = -0.38, 0.63), P = 0.586], MHC ΙΙa [(95%CI = -0.50, 0.65), P = 0.783] and MHC IIx [(95%CI = -1.08, 0.42), P = 0.355]. The findings of the present study indicate that the greater use of the dominant limbs for throwing actions and body movements in handball do not lead to altered MHC isoform composition compared to the non-dominant limbs.

• Klíčová slova
• Deltoid, handball, muscle biopsies, myosin, vastus lateralis,
• MeSH
• čtyřhlavý sval stehenní chemie   MeSH
• elektroforéza v polyakrylamidovém gelu MeSH
• lidé MeSH
• mladý dospělý MeSH
• musculus deltoideus chemie   MeSH
• protein - isoformy analýza   MeSH
• sporty fyziologie   MeSH
• těžké řetězce myosinu analýza   chemie   MeSH
• Check Tag
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• protein - isoformy MeSH
• těžké řetězce myosinu MeSH

Septins, a family of GTP-binding proteins that assemble into higher order structures, interface with the membrane, actin filaments and microtubules, and are thus important regulators of cytoarchitecture. Septin 9 (SEPT9), which is frequently overexpressed in tumors and mutated in hereditary neuralgic amyotrophy (HNA), mediates the binding of septins to microtubules, but the molecular determinants of this interaction remained uncertain. We demonstrate that a short microtubule-associated protein (MAP)-like motif unique to SEPT9 isoform 1 (SEPT9_i1) drives septin octamer-microtubule interaction in cells and in vitro reconstitutions. Septin-microtubule association requires polymerizable septin octamers harboring SEPT9_i1. Although outside of the MAP-like motif, HNA mutations abrogate this association, identifying a putative regulatory domain. Removal of this domain from SEPT9_i1 sequesters septins on microtubules, promotes microtubule stability and alters actomyosin fiber distribution and tension. Thus, we identify key molecular determinants and potential regulatory roles of septin-microtubule interaction, paving the way to deciphering the mechanisms underlying septin-associated pathologies. This article has an associated First Person interview with the first author of the paper.

• Klíčová slova
• Actin, Cytoskeleton, Microtubule, SEPT9, Septin,
• MeSH
• kontraktilní svazky * metabolismus   MeSH
• lidé MeSH
• mikrotubuly metabolismus   MeSH
• protein - isoformy genetika   metabolismus   MeSH
• proteiny asociované s mikrotubuly MeSH
• septiny * genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• protein - isoformy MeSH
• proteiny asociované s mikrotubuly MeSH
• SEPTIN9 protein, human MeSH Prohlížeč
• septiny * MeSH