Epithelial Cell Adhesion Molecule (EpCAM) , also known as GA733-2 antigen , is a type I transmembrane glycoprotein composed of an extracellular domain with two EGF-Like repeats and a cystenin-rich region , a transmembrane domain and a cytoplasmic domain. It modulates cell adhesion and proliferation. Its overexpression has been detected in many epithelial tumours and has been associated with high stage , high grade and a worse survival in some tumour types. EpCAM has been shown to function as a calcium-independent homophilic cell adhesion molecule that does not exhibit any obvious relationship to the four known cell adhesion molecule superfamilies. However , recent insights have revealed that EpCAM participates in not only cell adhesion , but also in proliferation , migration and differentiation of cells. In addition , recent study revealed that EpCAM is the Wnt-beta-catenin signaling target gene and may be used to facilitate prognosis. It has oncogenic potential and is activated by release of its intracellular domain , which can signal into the cell nucleus by engagement of elements of the wnt pathway.
Endothelial protein C receptor (EPCR), also known as activated protein C receptor (APC receptor) or PROCR, is a receptor for Protein C. Protein C plays an important role in many metabolism processes in humans and other animals after activated by binding to Endothelial protein C receptor (EPCR). Because of the EPCR is found primarily on endothelial cells (cells on the inside of blood vessels), activated protein C is found maily near endothelial cells. Protein C is pleiotropic, with two main functions: anticoagulation and cytoprotection. Which function will be performed depend on whether or not protein C remains bind to EPCR after activated. The anticoagulation occurs when it does not. In this case, protein C functions as an anticoagulant by irreversibly proteolytically inactivating Factor Va and Factor VIIIa, turning them into Factor Vi and Factor VIIIi respectively. When still bound to EPCR, activated protein C performs its cytoprotective effects, acting on the effector substrate PAR-1, protease-activated receptor-1. To a degree, APC's anticoagulant properties are independent of its cytoprotective ones, in that expression of one pathway is not affected by the existence of the other.
EPHA1 or EPH receptor A1 belongs to the ephrin receptor subfamily of the protein-tyrosine kinase family. Receptors in the EPH subfamily typically have a single kinase domain and an extracellular region containing a Cys-rich domain and 2 fibronectin type III repeats. An important role of Eph receptors and their ligands ephrins is to mediate cell-contact-dependent repulsion. Eph receptors and ephrins also act at boundaries to channel neuronal growth cones along specific pathways, restrict the migration of neural crest cells, and via bidirectional signaling prevent intermingling between hindbrain segments. Eph receptors and ephrins can also trigger an adhesive response of endothelial cells and are required for the remodeling of blood vessels. Eph receptors and ephrins have emerged as key regulators of the repulsion and adhesion of cells that underlie the establishment, maintainence, and remodeling of patterns of cellular organization. The ephrins and Eph receptors are implicated as positional labels that may guide the development of neural topographic maps.
Eph receptor A2 is a member of the ephrin receptor subfamily of the protein-tyrosine kinase family. The Eph receptors' corresponding family of ligands are the ephrins anchored to cell surfaces. The ephrins and Eph receptors are implicated as positional labels that may guide the development of neural topographic maps. They have also been found implicated in embryonic patterning, neuronal targeting, vascular development and adult neovascularization. The large family of ligands and receptors may make a major contribution to the accurate spatial patterning of connections and cell position in the nervous system. Furthermore, elevated expression of Eph receptors and ephrin ligands is associated with tumors and associated tumor vasculature, suggesting the Eph receptors and ephrin ligands also play critical roles in tumor angiogenesis and tumor growth. Unlike most Eph kinases, which are primarily expressed during development, EphA2 is primarily found in adult human epithelial cells. The cellular functions of EphA2 may be regulating cell growth, survival, migration, and angiogenesis.Unlike other receptor tyrosine kinases, ligand binding is not necessary for EphA2. Rather, the ligand appears to regulate EphA2 subcellular localization and its interactions with downstream adapter and signaling proteins. Eph receptor A2(EphA2) has been demonstrated to critically regulate tumor cell growth, migration and invasiveness. Eph receptor A2(EphA2) is frequently overexpressed and functionally altered in aggressive tumor cells, and that these changes promote metastatic character.
EPHA3 gene belongs to the ephrin receptor subfamily of the protein-tyrosine kinase family. EPH and EPH-related receptors have been implicated in mediating developmental events, particularly in the nervous system. The ephrin receptors are divided into 2 groups based on the similarity of their extracellular domain sequences and their affinities for binding ephrin-A and ephrin-B ligands. EPHA3 gene encodes a protein that binds ephrin-A ligands. EPHA3 is involved in the retinotectal mapping of neurons. It may also control the segregation but not the guidance of motor and sensory axons during neuromuscular circuit development.
EPH receptor A4 (ephrin type-A receptor 4), also known as EphA4, belongs to the ephrin receptor subfamily of the protein-tyrosine kinase family which 16 known receptors (14 found in mammals) are involved: EPHA1, EPHA2, EPHA3, EPHA4, EPHA5, EPHA6, EPHA7, EPHA8, EPHA9, EPHA10, EPHB1, EPHB2, EPHB3, EPHB4, EPHB5, EPHB6. The Eph family of receptor tyrosine kinases (comprising EphA and EphB receptors) has been implicated in synapse formation and the regulation of synaptic function and plasticity6. EphA4 is enriched on dendritic spines of pyramidal neurons in the adult mouse hippocampus, and ephrin-A3 is localized on astrocytic processes that envelop spines. Eph receptor−mediated signaling, which is triggered by ephrins7, probably modifies the properties of synapses during synaptic activation and remodeling. Ephrin receptors are components of cell signalling pathways involved in animal growth and development, forming the largest sub-family of receptor tyrosine kinases (RTKs). The extracellular domain of an EphA4 interacts with ephrin ligands, which may be tethered to neighbouring cells. Ligand-mediated activation of Ephs induce various important downstream effects and Eph receptors have been studied for their potential roles in the development of cancer.
Lascia la tua email e seleziona le aree che vuoi seguire per ricevere novita di prodotto, approfondimenti tecnici e promozioni piu pertinenti.
Puoi scegliere le macro-aree Life Science e Diagnostica oppure le singole specializzazioni.
Seleziona uno o piu ambiti di interesse per ricevere comunicazioni piu utili e mirate.
Aggiornamenti su ricerca, strumentazione e applicazioni per il mondo Life Science.
Novita, approfondimenti e promozioni per laboratori diagnostici e flussi operativi.
2025 TEMA Ricerca - All Rights Reserved.
