Gap junctions are plasma membrane domains containing arrays of channels that exchange ions and small molecules between neighboring cells. Gap junctional intercellular communication enables cells to directly cooperate both electrically and metabolically. Several lines of evidence indicate that gap junctions are important in regulating cell growth and differentiation and for maintaining tissue homeostasis. Gap junction channels consist of a family of transmembrane proteins called connexins. Gap junctions are dynamic structures, and connexins have a high turnover rate in most tissues. Connexin43 (Cx43), the best-studied connexin isoform, has a half-life of 1.5-5 h; and its degradation involves both the lysosomal and proteasomal systems. Increasing evidence suggests that ubiquitin is important in the regulation of Cx43 endocytosis. Ubiquitination of Cx43 is thought to occur at the plasma membrane and has been shown to be regulated by protein kinase C and the mitogen-activated protein kinase pathway. Cx43 binds to the E3 ubiquitin ligase Nedd4, in a process modulated by Cx43 phosphorylation. The interaction between Nedd4 and Cx43 is mediated by the WW domains of Nedd4 and involves a proline-rich sequence conforming to a PY (XPPXY) consensus motif in the C terminus of Cx43. In addition to the PY motif, an overlapping tyrosine-based sorting signal conforming to the consensus of an YXXphi motif is involved in Cx43 endocytosis, indicating that endocytosis of gap junctions involves both ubiquitin-dependent and -independent pathways. Here, we discuss current knowledge on the ubiquitination of connexins.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1007/s00232-007-9050-z | DOI Listing |
Background: Although invasiveness is one of the major determinants of the poor glioblastoma (GBM) outcome, the mechanisms of GBM invasion are only partially understood. Among the intrinsic and environmental processes promoting cell-to-cell interaction processes, eventually driving GBM invasion, we focused on the pro-invasive role played by Extracellular Vesicles (EVs), a heterogeneous group of cell-released membranous structures containing various bioactive cargoes, which can be transferred from donor to recipient cells.
Methods: EVs isolated from patient-derived GBM cell lines and surgical aspirates were assessed for their pro-migratory competence by spheroid migration assays, calcium imaging, and PYK-2/FAK phosphorylation.
J Tissue Eng
January 2025
Department of Surgery, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
Mural cells are essential for maintaining the proper functions of microvasculatures. However, a key challenge of microvascular tissue engineering is identifying a cellular source for mural cells. We showed that , circulating fibrocytes (CFs) can (1) shear and stabilize the microvasculatures formed by vascular endothelial cells (VECs) in a collagen gel, (2) form gap junctions with VECs and (3) induce basement membrane formation.
View Article and Find Full Text PDFPhysiol Rep
February 2025
Berlin Institute of Health at Charité, Universitätsmedizin Berlin, Center of Functional Genomics, Berlin, Germany.
The zona glomerulosa (ZG) synthesizes the mineralocorticoid aldosterone. The primary role of aldosterone is the maintenance of volume and electrolyte homeostasis. Aldosterone synthesis is primarily regulated via tightly controlled oscillations in intracellular calcium levels in response to stimulation.
View Article and Find Full Text PDFJ Assist Reprod Genet
January 2025
Department of Veterinary Medicine, University of Sassari, Via Vienna 2, Sassari, Italy.
Purpose: This study aimed to evaluate the effectiveness of single versus group culture strategies for cumulus-oocyte complexes (COCs) derived from early antral follicles (EAFs), with the goal of optimizing culture conditions to increase oocyte availability for assisted reproductive technologies.
Methods: COCs isolated from EAFs (350-450 µm) from sheep ovaries were cultured in TCM199 medium supplemented with 0.15 µg/mL Zn as zinc sulfate, 10 IU/mL FSH, 10 ng/mL estradiol, 50 ng/mL testosterone, 50 ng/mL progesterone, and 5 µM Cilostamide.
Pharmaceutics
January 2025
Department of Pharmacology, School of Medicine, University of Mostar, 88000 Mostar, Bosnia and Herzegovina.
Background: This is a novel rat study using native peptide therapy, focused on reversing quadriceps muscle-to-bone detachment to reattachment and stable gastric pentadecapeptide BPC 157 per-oral therapy for shared muscle healing and function restoration.
Methods: Pharmacotherapy recovering various muscle, tendon, ligament, and bone lesions, and severed junctions (i.e.
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!