Transient receptor potential melastatin (TRPM) channels, a subfamily of the TRP superfamily, constitute a diverse group of ion channels involved in mediating crucial cellular processes like calcium homeostasis. These channels exhibit complex regulation, and one of the key regulatory mechanisms involves their interaction with calmodulin (CaM), a cytosol ubiquitous calcium-binding protein. The association between TRPM channels and CaM relies on the presence of specific CaM-binding domains in the channel structure. Upon CaM binding, the channel undergoes direct and/or allosteric structural changes and triggers down- or up-stream signaling pathways. According to current knowledge, ion channel members TRPM2, TRPM3, TRPM4, and TRPM6 are directly modulated by CaM, resulting in their activation or inhibition. This review specifically focuses on the interplay between TRPM channels and CaM and summarizes the current known effects of CaM interactions and modulations on TRPM channels in cellular physiology.
Excessive osteoclast differentiation and/or bone resorptive function causes a gradual loss of bone, leading to the pathogenesis of bone diseases such as osteoporosis (OP). In this study, a sulfated glucuronorhamnoxylan polysaccharide (designated SPS-CF) of the green alga Capsosiphon fulvescens was evaluated for anti-osteoporotic activity using osteoclastic cells differentiated from RAW264.7 macrophages by receptor activator of NF-κB ligand (RANKL) treatment and ovariectomized (OVX) female mice as a postmenopausal OP model. With negligible cytotoxicity, SPS-CF (50 μg/mL) significantly suppressed tartrate-resistant acid phosphatase (TRAP) activity, actin ring formation, and expression of matrix metalloproteinase 9 (MMP-9), cathepsin K, TRAF6, p-Pyk2, c-Cbl, c-Src, gelsolin, carbonic anhydrase II (CA II), and integrin β3, indicating that SPS-CF inhibits the differentiation and bone resorptive function of osteoclasts. Removal of sulfate groups from SPS-CF abolished its anti-osteoclastogenic activities, demonstrating that sulfate groups are critical for its activity. Oral administration of SPS-CF (400 mg/kg/day) to OVX mice significantly augmented the bone mineral density (BMD) and serum osteoprotegerin (OPG)/RANKL ratio. These results demonstrated that SPS-CF exerts significant anti-osteoporotic activity by dampening osteoclastogenesis and bone resorption via downregulation of TRAF6-c-Src-Pyk2-c-Cbl-gelsolin signaling and augmentation of serum OPG/RANKL ratios in OVX mice, suggesting that SPS-CF can be a novel anti-osteoporotic compound for treating postmenopausal OP.
- MeSH
- buněčná diferenciace MeSH
- Chlorophyta * metabolismus MeSH
- faktor 6 asociovaný s receptory TNF metabolismus MeSH
- fokální adhezní kinasa 2 metabolismus MeSH
- gelsolin metabolismus MeSH
- kyselá fosfatasa rezistentní k tartarátu metabolismus MeSH
- myši MeSH
- NF-kappa B metabolismus MeSH
- osteoporóza * farmakoterapie MeSH
- resorpce kosti * farmakoterapie MeSH
- sírany metabolismus MeSH
- zvířata MeSH
- Check Tag
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Constantly increasing attention to bioengineered proteins has led to the rapid development of new functional targets. Here we present the biophysical and functional characteristics of the newly designed CaM/AMBN-Ct fusion protein. The two-domain artificial target consists of calmodulin (CaM) and ameloblastin C-terminus (AMBN-Ct). CaM as a well-characterized calcium ions (Ca2+) binding protein offers plenty of options in terms of Ca2+ detection in biomedicine and biotechnologies. Highly negatively charged AMBN-Ct belongs to intrinsically disordered proteins (IDPs). CaM/AMBN-Ct was designed to open new ways of communication synergies between the domains with potential functional improvement. The character and function of CaM/AMBN-Ct were explored by biophysical and molecular modelling methods. Experimental studies have revealed increased stability and preserved CaM/AMBN-Ct function. The results of molecular dynamic simulations (MDs) outlined different interface patterns between the domains with potential allosteric communication within the fusion.
- MeSH
- kalmodulin chemie MeSH
- lidé MeSH
- molekulární modely MeSH
- proteiny zubní skloviny chemie metabolismus MeSH
- sekvence aminokyselin genetika MeSH
- vápník chemie MeSH
- vazba proteinů fyziologie MeSH
- vazebná místa fyziologie MeSH
- vnitřně neuspořádané proteiny chemie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Myeloproliferatívne neoplázie (MPN) tvoria skupinu príbuzných klonálnych hematologických porúch s prekrývajúcim sa fenotypom. Hlavným znakom MPN je nadprodukcia plne diferencovaných myeloidných buniek, chronický zápal a riziko transformácie do sekundárnej akútnej myeloidnej leukémie. Klonálna proliferácia je riadená rôznymi somatickými mutáciami, najčastejšie mutáciami v géne kódujúcom Janusovu kinázu 2 (JAK2). Fenotypová diverzita, špecifická pre MPN, však nemôže prameniť len zo súčinnosti rôznych riadiacich mutácií s mutáciami prídavnými, ktoré sú popisované u pacientov s MPN. Naopak, za heterogenitou MPN stojí celý rad genetických ako aj negenetických faktorov. Ako významný determinant, predovšetkým rozvoja klonálnej hematopoézy, sa ukazuje genetická predispozícia. Náš súhrnný článok prináša prehľad najnovších poznatkov týkajúcich sa komplexnosti patobiológie chromozóm Filadelfia (Ph) -negatívnych MPN.
Myeloproliferative neoplasms (MPNs) represent a group of related clonal haematological disorders with overlapping phenotypes. The main typical features are excessive production of fully differentiated myeloid cells, chronic inflammation and a tendency to transform to acute myeloid leukaemia. Clonal proliferation in MPN is driven by various somatic mutations, most notably involving Janus kinase 2 (JAK2). However, MPN phenotypic diversity cannot be explained only by cooperation of acquired driver mutations with additional somatic mutations detected in MPN patients. Indeed, MPN initiation and clinical phenotype is a product of complex interactions involving both genetic and non-genetic factors. Recently, genetic predisposition appeared as an important determinant of MPN pathophysiology, particularly of clonal expansion. This review provides insights into complex, newly emerging factors contributing to Philadelphia chromosome (Ph) -negative MPN pathobiology.
- MeSH
- chronická myeloidní leukemie etiologie genetika MeSH
- genetická predispozice k nemoci MeSH
- Janus kinasa 2 MeSH
- kalretikulin MeSH
- lidé MeSH
- myeloproliferativní poruchy * genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
Calreticulin (CALR) is an endoplasmic reticulum (ER)-resident protein involved in a spectrum of cellular processes. In healthy cells, CALR operates as a chaperone and Ca2+ buffer to assist correct protein folding within the ER. Besides favoring the maintenance of cellular proteostasis, these cell-intrinsic CALR functions support Ca2+-dependent processes, such as adhesion and integrin signaling, and ensure normal antigen presentation on MHC Class I molecules. Moreover, cancer cells succumbing to immunogenic cell death (ICD) expose CALR on their surface, which promotes the uptake of cell corpses by professional phagocytes and ultimately supports the initiation of anticancer immunity. Thus, loss-of-function CALR mutations promote oncogenesis not only as they impair cellular homeostasis in healthy cells, but also as they compromise natural and therapy-driven immunosurveillance. However, the prognostic impact of total or membrane-exposed CALR levels appears to vary considerably with cancer type. For instance, while genetic CALR defects promote pre-neoplastic myeloproliferation, patients with myeloproliferative neoplasms bearing CALR mutations often experience improved overall survival as compared to patients bearing wild-type CALR. Here, we discuss the context-dependent impact of CALR on malignant transformation, tumor progression and response to cancer therapy.
- MeSH
- kalretikulin genetika metabolismus MeSH
- lidé MeSH
- mutace MeSH
- myeloproliferativní poruchy metabolismus patologie MeSH
- nádory metabolismus patologie MeSH
- prezentace antigenu MeSH
- prognóza MeSH
- signální transdukce MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Kinesin-like calmodulin-binding protein (KCBP) is a unique kinesin with half kinesin and half myosin, with kinesin motor domain at C-terminus and myosin tail homology region 4 (MyTH4) and band 4.1, ezrin, radixin, moesin (FERM) domains at N-terminus. The special structure endows KCBP multi-intracellular functions, including cell division, trichome morphogenesis in plants, and flagellar function in algae. However, little is known about the molecular mechanism underlying these functions. Here, we identified a molecular chaperone Hsp90 as a novel binding partner with KCBP in Dunaliella salina using a yeast two-hybrid screen. Further analysis showed that Hsp90 interacted with both the N-terminal and C-terminal of DsKCBP. Since Hsp90 was involved in the stability and proteolytic turnover of numerous proteins, whether Hsp90 regulated the degradation of DsKCBP was investigated. Our results showed that both Hsp90 and DsKCBP presented in the purified proteasome, and the interaction of DsKCBP-Hsp90 was inhibited upon Hsp90 inhibitor geldanamycin treatment. The level of DsKCBP proteins was diminished remarkably indicating that the disassociation of DsKCBP from Hsp90 accelerated the degradation of the former. Furthermore, immunofluorescence results showed that the localization of DsKCBP at basal body and flagella was disappeared by Hsp90 inhibition. The increased mRNA level of DsKCBP during flagellar assembly was not obvious by geldanamycin treatment. These data provided evidence that Hsp90 protected DsKCBP from degradation by proteasome and was involved in the role of DsKCBP in flagellar assembly.
In some settings, cancer cells responding to treatment undergo an immunogenic form of cell death that is associated with the abundant emission of danger signals in the form of damage-associated molecular patterns. Accumulating preclinical and clinical evidence indicates that danger signals play a crucial role in the (re-)activation of antitumor immune responses in vivo, thus having a major impact on patient prognosis. We have previously demonstrated that the presence of calreticulin on the surface of malignant blasts is a positive prognostic biomarker for patients with acute myeloid leukemia (AML). Calreticulin exposure not only correlated with enhanced T-cell-dependent antitumor immunity in this setting but also affected the number of circulating natural killer (NK) cells upon restoration of normal hematopoiesis. Here, we report that calreticulin exposure on malignant blasts is associated with enhanced NK cell cytotoxic and secretory functions, both in AML patients and in vivo in mice. The ability of calreticulin to stimulate NK-cells relies on CD11c+CD14high cells that, upon exposure to CRT, express higher levels of IL-15Rα, maturation markers (CD86 and HLA-DR) and CCR7. CRT exposure on malignant blasts also correlates with the upregulation of genes coding for type I interferon. This suggests that CD11c+CD14high cells have increased capacity to migrate to secondary lymphoid organs, where can efficiently deliver stimulatory signals (IL-15Rα/IL-15) to NK cells. These findings delineate a multipronged, clinically relevant mechanism whereby surface-exposed calreticulin favors NK-cell activation in AML patients.
- MeSH
- aktivace lymfocytů MeSH
- akutní myeloidní leukemie * terapie MeSH
- buňky NK MeSH
- cytotoxicita imunologická MeSH
- interleukin-15 MeSH
- kalretikulin * genetika metabolismus MeSH
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, U.S. Gov't, Non-P.H.S. MeSH
Immunogenic cell death (ICD), a functionally peculiar type of apoptosis, represents a unique way to deliver danger-associated molecular patterns (DAMPs) to the tumor microenvironment. Once emitted by dying cancer cells, DAMPs orchestrate antigen-specific immune responses by acting on both innate and adaptive components of the immune system. Accumulating preclinical and clinical evidence indicates that one of these DAMPs, calreticulin (CALR) represents a novel powerful prognostic biomarker, reflecting the activation of a clinically relevant anticancer immune response in different cancer malignancies. Therefore, the assessment of CALR emission can provide a therapeutic tool for the stratification of cancer patients and the identification of individuals that are intrinsically capable to respond to a particular treatment. Here we describe methods for the quantification of CALR exposure in the tumor microenvironment of cancer patients by flow cytometry and immunohistochemistry.
- MeSH
- imunogenní buněčná smrt * MeSH
- imunohistochemie metody MeSH
- kalretikulin analýza imunologie MeSH
- lidé MeSH
- nádorové biomarkery analýza imunologie MeSH
- nádorové mikroprostředí MeSH
- nádory imunologie patologie MeSH
- průtoková cytometrie metody MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
Molecular determinants of the binding of various endogenous modulators to transient receptor potential (TRP) channels are crucial for the understanding of necessary cellular pathways, as well as new paths for rational drug designs. The aim of this study was to characterise interactions between the TRP cation channel subfamily melastatin member 4 (TRPM4) and endogenous intracellular modulators-calcium-binding proteins (calmodulin (CaM) and S100A1) and phosphatidylinositol 4, 5-bisphosphate (PIP2). We have found binding epitopes at the N- and C-termini of TRPM4 shared by CaM, S100A1 and PIP2. The binding affinities of short peptides representing the binding epitopes of N- and C-termini were measured by means of fluorescence anisotropy (FA). The importance of representative basic amino acids and their combinations from both peptides for the binding of endogenous TRPM4 modulators was proved using point alanine-scanning mutagenesis. In silico protein-protein docking of both peptides to CaM and S100A1 and extensive molecular dynamics (MD) simulations enabled the description of key stabilising interactions at the atomic level. Recently solved cryo-Electron Microscopy (EM) structures made it possible to put our findings into the context of the entire TRPM4 channel and to deduce how the binding of these endogenous modulators could allosterically affect the gating of TRPM4. Moreover, both identified binding epitopes seem to be ideally positioned to mediate the involvement of TRPM4 in higher-order hetero-multimeric complexes with important physiological functions.
- MeSH
- akvaporiny chemie metabolismus MeSH
- interakční proteinové domény a motivy * MeSH
- kalmodulin chemie metabolismus MeSH
- kationtové kanály TRPM chemie metabolismus MeSH
- kinetika MeSH
- konformace proteinů MeSH
- lidé MeSH
- molekulární modely MeSH
- multiproteinové komplexy chemie metabolismus MeSH
- peptidové fragmenty MeSH
- proteiny S100 chemie metabolismus MeSH
- sekvence aminokyselin MeSH
- vazba proteinů MeSH
- vazebná místa * MeSH
- vztahy mezi strukturou a aktivitou MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Cystic echinococcosis (CE) is a zoonotic disease caused by the tapeworms of the Echinococcus granulosus sensu lato complex, which have worldwide distribution. No data on the circulation of genotypes of the E. granulosus complex in intermediate hosts in endemic areas in Calabria are available. The aims of our study were to evaluate the dispersal of genotypes of the E. granulosus complex in Calabria and to characterise parasite isolates by Sanger sequencing and phylogenetic analysis. We collected 71 animal samples from pigs, wild boars, sheep, cattle and goats. The first PCR screening analysis targeted three partial genomic regions: the cytochrome c oxidase subunit 1 (cox1), calreticulin protein (cal) and NADH dehydrogenase subunit 1 (nad1); this identified 28 parasitic cysts. Bidirectional sequencing of cox1 amplicons and phylogenetic analysis allowed us to characterise all isolates. Molecular analyses of 28 newly generated cox1 sequences revealed that most wild boars (n = 16) and three pigs were parasitised by the larval stage of Taenia hydatidena Pallas, 1766, called cysticercus tenuicollis. Two isolates from wild boars were identified as Echinococcus canadensis Webster and Cameron, 1961 (G7), while five sheep and two goats were infected with E. granulosus G1 (sheep strain) and G1 microvariant (previously reported as G2 genotype or Tasmanian sheep strain), respectively. These molecular findings should prompt further and more extensive studies, to elucidate regional transmission patterns and to guide control programs.
- MeSH
- Echinococcus granulosus klasifikace genetika izolace a purifikace MeSH
- echinokokóza parazitologie veterinární MeSH
- fylogeneze MeSH
- genotyp MeSH
- kalretikulin analýza MeSH
- kozy MeSH
- NADH-dehydrogenasa analýza MeSH
- nemoci koz parazitologie MeSH
- nemoci ovcí parazitologie MeSH
- nemoci prasat parazitologie MeSH
- nemoci skotu parazitologie MeSH
- ovce MeSH
- prasata MeSH
- proteiny červů analýza MeSH
- respirační komplex IV analýza MeSH
- rozšíření zvířat MeSH
- skot MeSH
- zvířata MeSH
- Check Tag
- skot MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- Geografické názvy
- Itálie MeSH
