To clarify the molecular pathways governing hematopoietic stem cell (HSC) development, we screened a fetal liver (FL) HSC cDNA library and identified a unique gene, hematopoietic expressed mammalian polycomb (hemp), encoding a protein with a zinc-finger domain and four malignant brain tumor (mbt) repeats. To investigate its biological role, we generated mice lacking Hemp (hemp(-/-)). Hemp(-/-) mice exhibited a variety of skeletal malformations and died soon after birth. In the FL, hemp was preferentially expressed in the HSC and early progenitor cell fractions, and analyses of fetal hematopoiesis revealed that the number of FL mononuclear cells, including HSCs, was reduced markedly in hemp(-/-) embryos, especially during early development. In addition, colony-forming and competitive repopulation assays demonstrated that the proliferative and reconstitution abilities of hemp(-/-) FL HSCs were significantly impaired. Microarray analysis revealed alterations in the expression levels of several genes implicated in hematopoietic development and differentiation in hemp(-/-) FL HSCs. These results demonstrate that Hemp, an mbt-containing protein, plays essential roles in HSC function and skeletal formation. It is also hypothesized that Hemp might be involved in certain congenital diseases, such as Klippel-Feil anomaly.
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http://dx.doi.org/10.1073/pnas.1003403108 | DOI Listing |
Comp Biochem Physiol C Toxicol Pharmacol
January 2025
Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, Guangdong 510300, China. Electronic address:
The small abalone (Haliotis diversicolor) is an economic shellfish cultured in the south coast of China. In recent years, the frequent occurrence of the disease has led to significant mortality in abalone farms. Deleted in malignant brain tumors 1 (DMBT1), a member of the scavenger receptor cysteine-rich (SRCR) protein family, plays an important role in host defense.
View Article and Find Full Text PDFPharmacol Res
January 2025
State Key Laboratory of Frigid Zone Cardiovascular Disease, Department of Cardiovascular Surgery, General Hospital of Northern Theater Command, Shenyang 110016, Liaoning, China. Electronic address:
Numerous studies conducted in recent years indicate that mammalian E3 ubiquitin ligases serve as key regulators in the maintenance of cellular homeostasis by targeting the ubiquitination of substrate proteins and activating downstream signaling pathways. SYVN1, an E3 ubiquitin ligase, is characterized by its significant functions in regulating various biological processes, including molecular mechanisms related to gene expression, signaling pathways, and cell death, among others. Consequently, SYVN1 plays a crucial role in both normal human physiology and the pathogenesis of various diseases, such as oncogenesis, cardiovascular disorders, immune regulation, skeletal anomalies, and neurological diseases.
View Article and Find Full Text PDFMech Ageing Dev
January 2025
Department Oral & Maxillofacial Surgery/Pathology, Amsterdam Movement Sciences & Amsterdam Bone Center (ABC), Amsterdam University Medical Center location Vrije Universiteit Amsterdam & Academic Center for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3004, 1081 LA Amsterdam, the Netherlands; TEC-MMG-LIS Lab, European Space Agency (ESA), European Space Research and Technology Center (ESTEC), Keplerlaan 1, 2201 AZ Noordwijk, the Netherlands.
The Linker of Nucleoskeleton and Cytoskeleton (LINC) complex plays a crucial role in connecting the nuclear envelope to the cytoskeleton, providing structural support to the nucleus and facilitating mechanical signaling between the extracellular environment and the nucleus. Research in mechanobiology onboard the International Space Station (ISS) and in simulated microgravity (SMG) highlight the importance of gravity in functional mechanotransduction. Although the altered gravity research regarding mechanobiology has been greatly focused on the cytoskeleton and the extracellular matrix (ECM), recent research demonstrates that SMG also induces changes in nuclear mechanics and gene expression patterns, which have been shown to be LINC complex dependent.
View Article and Find Full Text PDFJ Bacteriol
January 2025
Department of Microbiology, Howard Taylor Ricketts Laboratory, The University of Chicago, Chicago, Illinois, USA.
Protein secretion is an essential cell process in bacteria, required for cell envelope biogenesis, export of virulence factors, and acquisition of nutrients, among other important functions. In the Sec secretion pathway, signal peptide-bearing precursors are recognized by the SecA ATPase and pushed across the membrane through a translocon channel made of the proteins SecY, SecE, and SecG. The Sec pathway has been extensively studied in the model organism , but the Sec pathways of other bacteria such as the human pathogen differ in important ways from this model.
View Article and Find Full Text PDFmBio
January 2025
Shanghai Institute of Infectious Disease and Biosecurity, Fudan University, Shanghai, China.
Unlabelled: The KREMEN1 (KRM1) protein is a cellular receptor for multiple enteroviruses that cause hand, foot, and mouth disease (HFMD), including coxsackievirus CVA2, CVA3, CVA4, CVA5, CVA6, CVA10, and CVA12. The molecular basis for the broad recognition of these viruses by the KRM1 receptor remains unclear. Here, we report the indispensable role of the completely conserved VP2 capsid protein residue K140 (designated K2140) in mediating receptor recognition and infection by CVA10 and other KRM1-dependent enteroviruses.
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