Project description:Talin-1 (TLN1) is best known to activate integrin receptors and transmit mechanical stimuli to the actin cytoskeleton at focal adhesions. However, the localization of TLN1 is not restricted to focal adhesions. By utilizing both subcellular fractionations and confocal microscopy analyses, we show that TLN1 localizes to the nucleus in several human cell lines, where it is tightly associated with the chromatin. Importantly, siRNA-mediated depletion of endogenous TLN1 triggers extensive changes in the gene expression profile of human breast epithelial cells. To determine the functional impact of nuclear TLN1, we expressed a TLN1 fusion protein containing a nuclear localization signal. Our findings revealed that accumulation of nuclear TLN1 alters the expression of a subset of genes and impairs the formation of cell-cell clusters. This study introduces an additional perspective on the canonical view of TLN1 subcellular localization and function.
Project description:Previously, we suggested a cytosolic role for the histone-methyltransferase Ezh2 in regulating lymphocyte activation, but molecular mechanisms underpinning this extra-nuclear function remained unclear. Here we show that Ezh2 regulates integrin-signaling and adhesion dynamics of neutrophils and dendritic cells. Ezh2 deficiency impaired integrin-dependent transendothelial migration of innate leukocytes and restricted disease progression in an animal model of multiple sclerosis. Direct methylation of talin, a key regulatory molecule in cell migration, by Ezh2 disrupted talin binding to F-actin and thereby promoted adhesion structure turnover. This regulatory effect was abolished by targeted disruption of Ezh2 interactions with Vav1. Our studies reveal a novel extra-nuclear function for Ezh2 in regulating adhesion dynamics with implications for leukocyte migration, immune responses and potentially pathogenic processes. Control and Ezh2-deficient bone marrow derived immature and mature dendritic cells were analyzed in triplicates
Project description:Previously, we suggested a cytosolic role for the histone-methyltransferase Ezh2 in regulating lymphocyte activation, but molecular mechanisms underpinning this extra-nuclear function remained unclear. Here we show that Ezh2 regulates integrin-signaling and adhesion dynamics of neutrophils and dendritic cells. Ezh2 deficiency impaired integrin-dependent transendothelial migration of innate leukocytes and restricted disease progression in an animal model of multiple sclerosis. Direct methylation of talin, a key regulatory molecule in cell migration, by Ezh2 disrupted talin binding to F-actin and thereby promoted adhesion structure turnover. This regulatory effect was abolished by targeted disruption of Ezh2 interactions with Vav1. Our studies reveal a novel extra-nuclear function for Ezh2 in regulating adhesion dynamics with implications for leukocyte migration, immune responses and potentially pathogenic processes.
Project description:SLK controls the cytoskeleton, cell adhesion and migration. Analysis of a protein kinase phosphorylation site dataset showed that podocyte adhesion proteins – paxillin, vinculin and talin-1 may be potential SLK substrates. The project examines if these adhesion proteins are substrates of SLK.
Project description:Accumulated research has suggested the importance of the adhesion molecules modulation as therapeutic approach for bronchial asthma. Adhesion molecules expression alteration contributes to the pathogenesis of asthma. In order to probe the relationship between expression imbalance of adhesion molecules and asthma pathogenesis, expression profiling of adhesion molecules was performed using cDNA microarray. The results showed that there were various adhesion molecules with abnormal expressions in peripheral blood leucocytes of asthma patients.
Project description:Cellular senescence is a phenotype characterized by cessation of cell division, which can be caused by exhaustive replication or environmental stress. It is involved in age-related pathophysiological conditions and affects both the cellular cytoskeleton and the prime cellular mechanosensors, focal adhesion complexes. While the size of focal adhesions increases during senescence, it is unknown if and how this is accompanied by a remodeling of the internal focal adhesion structure. Our study uses metal-induced energy transfer to study the axial dimension of focal adhesion proteins from oxidative-stress-induced senescent cells with nanometer precision, and compares these to unstressed cells. We influenced cytoskeletal tension and the functioning of mechanosensitive ion channels using drugs and studied the combined effect of senescence and drug intervention on the focal adhesion structure. We find that H 2 O 2 induced restructuring of the focal adhesion complex indicates a loss of tension and altered talin complexation. Mass spectroscopy-based proteomics confirmed the differential regulation of several cytoskeletal proteins induced by H 2 O 2 treatment.
Project description:Accumulated research has suggested the importance of the adhesion molecules modulation as therapeutic approach for bronchial asthma. Adhesion molecules expression alteration contributes to the pathogenesis of asthma. In order to probe the relationship between expression imbalance of adhesion molecules and asthma pathogenesis, expression profiling of adhesion molecules was performed using cDNA microarray. The results showed that there were various adhesion molecules with abnormal expressions in peripheral blood leucocytes of asthma patients. RNA was extracted from leucocytes in peripheral blood of 4 normal adults and 6 asthma patients by using TRIzol Reagent. Microarray expression studies were performed using the GEArray Q Series Human Extracellular Matrix & Adhesion Molecules Gene Array (SABiosciences Corporation, USA). This microarray profiles the expression of 96 genes key to the functions of cell adhesion. A negative control (PUC18DNA and blank), and the housekeeping genes including β-actin, GAPDH, Cyclophilin A and ribose body protein L13a were spread on each chip.