Browsing by Subject "Actin"
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- PublicationOpen AccessControl of cell shape and plasticity during development and disease by the actin-binding protein Drebrin(Murcia : F. Hernández, 2010) Dun, Xin-peng; Chilton, John K.Drebrin is an actin-binding protein, originally identified in neuronal cells, involved in the regulation of actin filament organisation, especially during the formation of neurites and cell protrusions of motile cells. Drebrin is found in diverse non-neuronal cells, primarily in association with cell processes and intercellular junctions where it again plays a key role in actin remodelling. The downregulation of Drebrin in Alzheimer’s Disease and Down Syndrome and conversely its upregulation in various carcinomas indicate that Drebrin is an important component of the pathogenesis of multiple diseases.
- PublicationOpen AccessCytoskeleton proteins, the structural basis of T-lymphocyte and TEC restructure during rapid thymus regeneration(Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2025) Wen, Xunuo; Gao, Jianli; Biología Celular e HistologíaThymus regeneration is the main way for humans to combat immune degeneration and immunosenescence. The interesting cycle of thymus degeneration and regeneration achieves the renewal of adaptive immunity, which is crucial for reconstructing cellular immunity. Rapid thymic regeneration is the main renewal mode after various acute stress-induced thymic involutions, such as radiation, immunosuppressants, and starvation. The cytoskeleton is a key regulator of immune response by affecting the structure and function of immune cells. Our team has conducted years of research on rapid thymic regeneration and found that some types of cytoskeletal proteins, such as F-actin/G-actin, the Thymosin β family, ERM (Ezrin/Radixin/ Moesin), and WAVE2, play a critical role in the spatial development of thymic epithelial cells (TECs), and finally regulate the regeneration of the thymus by modulating the skeleton of TECs and T lymphocytes. Here, we summarize the current understanding of cytoskeleton proteins and cell restructure of TECs or T lymphocytes and its relationship with the regeneration of the thymus.
- PublicationOpen AccessEffects of phthalate esters on actin cytoskeleton of Py1a rat osteoblasts(Murcia : F. Hernández, 2002) Marchetti, L.; Sabbieti, M.G.; Menghi, M.; Materazzi, S.; Hurley, M.M.; Menghi, GiovannaWe evaluated, by confocal laser scanning microscopy, the actin cytoskeleton of immortalized rat Py1a osteoblasts treated with phthalate esters (butyl benzyl phthalate, BBP and dibutyl phthalate, DBP), endocrine disruptors with estrogenic activity. We observed some peculiar modifications of actin cytoskeleton and cells changing from a spindle shape to a rounded form. In particular, F-actin formed thick bundles around the cell membrane but only a weak labeling was observed in rounded cells. Also influence on apoptosis and short-term effects on FGF-2 were studied. It was found that BBP and DBP exert their action in a similar way, act in a transient manner and do not induce apoptosis.
- PublicationOpen AccessImmunohistochemical change of actin in exprerimental myocardial ischemia. Its usefulness to detect very early myocardial damages(Murcia : F. Hernández, 1987) Shozo Nishida; Shingo Hiruma; Shigeo HashimotoPathomorphological diagnosis of acute myocardial infarction has many problems in human autopsy materials less than 4 to 6 hours after clinical onset and in rats 2 to 3 hours after experimental coronary occlusion. Since immunohistochemical reaction deuends - ~ on the antigei determinant site of the material, chañges in the reaction may reflect alterations at the molecular level in myocardial fibers. With this consideration in mind, the effectiveness of diagnosing infarction at the earliest (possible) stage, and the changes of actin filaments were investigated through experiments, using immunohistochemical methods involving anti-actin antibodies produced from chicken gizzards in our laboratory. The left coronary arteries of rats were ligated to produce ischemia. Dehydrogenases were shown to be still present by triphenyltetrazolium chloride (TTC) reaction, but the anti-actin antibody reaction had disappeared in areas corresponding to the ischemic sites. However, on electron microscopic examination of these sites, actin fibers were clearly revealed. In the case of ischemia lasting for more than 6 hours, the anti-actin antibody reaction had disappeared, corresponding to the disappearance of the TTC reaction. At this stage, myocardial actin fibers were revealed by electron microscopic examination. These results indicate that ischemia induces some type of biochemical degeneration at the molecular level of myocardial actin, most likely the change of actin polymerization. Moreover, they show that the anti-actin antibody technique is capable of detecting such very early degenerative and ischemic changes proving itself to be better suited for determining the range and degree of early infarction.
- PublicationOpen AccessIon channels and actin: A tale of two friends(Universidad de Murcia, Departamento de Histología e Histopatología, 2025) Sesti Federico; Forzisi Elena; Biología Celular e HistologíaAn increasing number of studies highlight ion channels as multifunctional proteins involved in diverse cellular processes, including proliferation, differentiation, adhesion, migration, morphology, and programmed cell death (apoptosis). Given these broad roles, it is not surprising that ion channels interact closely with actin, a ubiquitous cytoskeletal component that participates in a vast array of biological functions. Ion channels depend on the actin cytoskeleton for essential activities such as trafficking to and from the plasma membrane. Conversely, actin dynamics are often modulated by ion channels during various cellular events. In this review, we provide an overview of the field and discuss key examples that reveal emerging patterns in the bidirectional interactions between ion channels and the actin cytoskeleton
- PublicationOpen AccessMetabolic control of cytokinesis by glucose cAMP–PKA signaling in fission yeast(Elsevier, 2025-09-19) Marín Castillo, Antonio; León Zaragoza, Sergio; Franco Sánchez, Alejandro; Vicente Soler, Jerónima; Núñez Hernández, Andrés; Soto Pino, Teresa; Madrid Mateo, María Isabel; Cansado Vizoso, José; Genética y Microbiología; Facultades de la UMU::Facultad de BiologíaCytokinesis, the final step of cell division, must be precisely coordinated with the cellular metabolic status, yet the underlying regulatory mechanisms remain poorly understood. Here we show that in Schizosaccharomyces pombe, glucose signaling promotes cytokinesis via the evolutionarily conserved cAMP–PKA signaling pathway. Loss of the Pka1 catalytic subunit delays assembly and constriction of the contractile actomyosin ring (CAR), whereas constitutive PKA activation enhances CAR integrity and accelerates cytokinesis. Mechanistically, Pka1 downregulates the basal activity of the stress-activated MAPK Sty1 under glucose-rich conditions, thereby stabilizing the formin For3 and its nucleated actin cables, which collaborate to regulate CAR dynamics. Remarkably, cAMP–PKA signaling also facilitates cytokinesis through a parallel, actin cable–independent mechanism. Additionally, mitochondrial respiration contributes to cytokinesis in the presence of glucose through a PKA-independent pathway. These findings reveal a multilayered network that links carbon source metabolism to cytoskeletal organization and underscore the importance of tight PKA activity control for robust cell division.
- PublicationOpen AccessProduction and characterization of a new monoclonal antibody, GR-ICOR-2, recognizing sarcomeric actin: analysis of the expression in the developing chick heart(Murcia : F. Hernández, 1994) Fernández, J.E.; Melguizo, C.; Prados, J.; Marchal, J.A.; Alvarez, L.; Aránega, A.We produced and characterized a specific monoclonal antibody (mAB) designated GR-ICOR-2. This mAb recognizes sarcomeric actin molecules (43 kDa) and was used in an immunohistochemical analysis of staining pattems in Harnburger and Hamilton's stages 18, 22 and 25 (HH 18, 22 and 25) embryonic chick hearts. Staining showed a mainly cytoplasmic distrubition in three regions: the atrioventricular (AV) canal cushion tissue, the primitive ventricle, and conal crests. In addition, this mAb-cross-reacted with rabbit and human cardiac and skeletal muscle tissue; but not with smooth muscle tissue.
- PublicationOpen AccessScratching the surface: Actin’ and other roles for the C-terminal Eps15 homology domain protein, EHD2(F. Hernández y Juan F. Madrid. Universidad de Murcia. Departamento de Biología Celular e Histología, 2014) Simone, Laura C.; Naslavsky, Naava; Caplan, SteveThe C-terminal Eps15 homology domaincontaining (EHD) proteins participate in multiple aspects of endocytic membrane trafficking. Of the four mammalian EHD proteins, EHD2 appears to be the most disparate, both in terms of sequence homology, and in subcellular localization/function. Since its initial description as a plasma membrane-associated protein, the precise function of EHD2 has remained enigmatic. Various reports have suggested roles for EHD2 at the plasma membrane, within the endocytic transport system, and even in the nucleus. For example, EHD2 facilitates membrane fusion/repair in muscle cells. Recently the focus has shifted to the role of EHD2 in regulating caveolae. Indeed, EHD2 is highly expressed in tissues rich in caveolae, including fat, muscle and blood vessels. This review highlights cumulative evidence linking EHD2 to actin-rich structures at the plasma membrane, where the plasma membraneassociated phospholipid phosphatidylinositol 4,5- bisphosphate controls EHD2 recruitment. Herein we examine the key pathways where EHD2 might function, and address its potential involvement in these processes.