Intra-thymic T cell development is coordinated by the regulatory actions of SATB1 genome organizer. In this report, we show that SATB1 is involved in the regulation of transcription and splicing, both of which displayed deregulation in knockout murine thymocytes. More importantly, we characterized a novel SATB1 protein isoform and described its distinct biophysical behavior, implicating potential functional differences compared to the commonly studied isoform.
View Article and Find Full Text PDFBackground: Knee osteoarthritis (OA) is one of the most common structural OA disorders globally. Incomplete understanding of the fundamental biological aspects of osteoarthritis underlies the current lack of effective treatment or disease modifying drugs.
Research Design And Methods: We implemented a systems approach by making use of the statistical network concepts in Weighted Gene Co-expression Analysis to reconstruct the organization of the core proteome network in chondrocytes obtained from OA patients and healthy individuals.
Proteome profile changes in Alzheimer's disease (AD) brains have been reported. However, it is unclear whether they represent a continuous process, or whether there is a sequential involvement of distinct proteins. To address this question, we used mass spectrometry.
View Article and Find Full Text PDFAlternative sigma factors control numerous aspects of bacterial life, including adaptation to physiological stresses, morphological development, persistence states and virulence. This is especially true for the physiologically complex actinobacteria. Here we report the development of a robust gene deletions system for TK24 based on a BAC library combined with the λ-Red recombination technique.
View Article and Find Full Text PDFProtein secretion is a central biological process in all organisms. Most studies dissecting bacterial secretion mechanisms have focused on Gram-negative cell envelopes such as that of However, proteomics analyses in Gram negatives is hampered by their outer membrane. Here we studied protein secretion in the Gram-positive bacterium TK24, in which most of the secretome is released in the growth medium.
View Article and Find Full Text PDFGram-positive bacteria are profuse secretors of polypeptides using complex, yet unknown mechanisms. Many of their secretory proteins are proteases that play important roles in the acquisition of amino acids from the environment. Other proteases regulate cellular proteostasis.
View Article and Find Full Text PDFBackground: Members of the genus Streptomyces are Gram-positive bacteria that are used as important cell factories to produce secondary metabolites and secrete heterologous proteins. They possess some of the largest bacterial genomes and thus proteomes. Understanding their complex proteomes and metabolic regulation will improve any genetic engineering approach.
View Article and Find Full Text PDFType III secretion (T3S), a protein export pathway common to Gram-negative pathogens, comprises a trans-envelope syringe, the injectisome, with a cytoplasm-facing translocase channel. Exported substrates are chaperone-delivered to the translocase, EscV in enteropathogenic and cross it in strict hierarchical manner, for example, first "translocators", then "effectors". We dissected T3S substrate targeting and hierarchical switching by reconstituting them using inverted inner membrane vesicles.
View Article and Find Full Text PDFFilamentous organisms of the genus Streptomyces play an important role in industrial production processes, due to their extensive secondary metabolism variability, as well as their ability to secrete efficiently large amounts of (heterologous) proteins. While genetic engineering tools are available to rapidly build up large strain libraries, the subsequent strain screening and bioprocess development still constitutes a bottleneck. This is due to the lack of reliable parallelized and accelerated cultivation techniques for morphologically challenging organisms.
View Article and Find Full Text PDFHuman embryonic stem cells (hESCs) are promising in regenerative medicine (RM) due to their differentiation plasticity and proliferation potential. However, a major challenge in RM is the generation of a vascular system to support nutrient flow to newly synthesized tissues. Here we refined an existing method to generate tight vessels by differentiating hESCs in CD34(+) vascular progenitor cells using chemically defined media and growth conditions.
View Article and Find Full Text PDFThe Type III secretion system (T3SS) is a protein export pathway that is widespread in Gram-negative bacteria and delivers effector proteins directly into eukaryotic cells. At its core lie the injectisome (a sophisticated transmembrane secretion apparatus) and a complex network of specialized chaperones that target secretory proteins to the antechamber of the injectisome. The assembly of the system, and the subsequent secretion of proteins through it, undergo fine-tuned, hierarchical regulation.
View Article and Find Full Text PDFBiological membranes define cells and cellular compartments and are essential in regulating bidirectional flow of chemicals and signals. Characterizing their protein content therefore is required to determine their function, nevertheless, the comprehensive determination of membrane-embedded sub-proteomes remains challenging. Here, we experimentally characterized the inner membrane proteome (IMP) of the model organism E.
View Article and Find Full Text PDFBackground: Osteoarthritis (OA) is a multi-factorial disease leading progressively to loss of articular cartilage and subsequently to loss of joint function. While hypertrophy of chondrocytes is a physiological process implicated in the longitudinal growth of long bones, hypertrophy-like alterations in chondrocytes play a major role in OA. We performed a quantitative proteomic analysis in osteoarthritic and normal chondrocytes followed by functional analyses to investigate proteome changes and molecular pathways involved in OA pathogenesis.
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