Receptor tyrosine kinase which binds promiscuously GPI-anchored ephrin-A family ligands residing on adjacent cells, leading to contact-dependent bidirectional signaling into neighboring cells. The signaling pathway downstream of the receptor is referred to as forward signaling while the signaling pathway downstream of the ephrin ligand is referred to as reverse signaling. Among GPI-anchored ephrin-A ligands, EFNA5 most probably constitutes the cognate/functional ligand for EPHA5. Functions as an axon guidance molecule during development and may be involved in the development of the retinotectal, entorhino-hippocampal and hippocamposeptal pathways. Together with EFNA5 plays also a role in synaptic plasticity in adult brain through regulation of synaptogenesis. Beside its function in the nervous system, the interaction of EPHA5 with EFNA5 mediates communication between pancreatic islet cells to regulate glucose-stimulated insulin secretion (By similarity).
We have isolated cDNA clones from a human fetal brain library that encode five members of the EPH sub-family of receptor protein tyrosine kinases (PTKs). Comparison of the DNA sequences of these receptors to the Genbank database reveals that two of our clones correspond to the previously identified HEK and ERK receptors, two are apparently human homologues of the mouse receptors Sek and Bsk and one is novel. With these additions, the number of known human EPH sub-family members is nine and the total in all vertebrate species is 13 making it the largest known sub-family of PTKs. Analysis of the expression pattern of EPH sub-family mRNAs reveals that some are expressed in a wide variety of adult tissues while others are quite restricted. Consistent with the amplification of these sequences from a fetal brain cDNA library, all five members which we have isolated are expressed in the brain. We have named these receptors HEK4, HEK5, HEK7, HEK8 and HEK11, following the nomenclature of Wicks et al. (1992) and the numbering convention set forth by Sajjadi et al. (1991). Analysis of these new EPH sub-family members will increase our understanding of the biology of this receptor family and their isolation will provide reagents for the identification of ligands for this large family of orphan receptors.
The chemotaxis process that directs the migration of an axon growth cone to a specific target site in response to a combination of attractive and repulsive cues.
Any intracellular signal transduction in which the signal is passed on within the cell via cyclic AMP (cAMP). Includes production of cAMP, and downstream effectors that further transmit the signal within the cell.
Any process that stops, prevents, or reduces the frequency, rate or extent of synapse assembly, the aggregation, arrangement and bonding together of a set of components to form a synapse.
The process whose specific outcome is the progression of a neuron over time, from initial commitment of the cell to a specific fate, to the fully functional differentiated cell.
Evidence
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Inferred from Expression PatternUniProtKB
J. Histochem. Cytochem. 47, 855-861 (1999)[PubMed:10375373]
To better understand the functional role of EphA5 in the adult human central nervous system (CNS), we performed an immunohistochemical mapping study. EphA5, like other members of the Elk/Eph family of receptor tyrosine kinases, was widely distributed in CNS neurons. However, the distribution of the neuronal staining was not uniform. The abundance of stained neurons appeared to increase from the forebrain to the hindbrain and spinal cord. Glial and endothelial tissue was unstained. These findings are consistent with the existence of receptor and ligand gradients in different brain regions. The localization of EphA5 to motor and sensory neurons is consistent with a role of EphA5 in neural plasticity, cell-cell recognition, and topographical orientation of neuronal systems.
Any process that modulates the frequency, rate or extent of the formation, arrangement of constituent parts, or disassembly of cytoskeletal structures comprising actin filaments and their associated proteins.
ISSOrtholog Curator
Regulation of insulin secretion involved in cellular response to glucose stimulusdefinition[GO:0061178]
Any process that modulates the frequency, rate or extent of the regulated release of insulin that contributes to the response of a cell to glucose.
Enzyme which catalyzes the transfer of the terminal phosphate of ATP to a specific tyrosine residue on its target protein. Many of these kinases play significant roles in development and cell division. Tyrosine-protein kinases can be divided into two subfamilies: receptor tyrosine kinases, which have an intracellular tyrosine kinase domain, a transmembrane domain and an extracellular ligand-binding domain; and non-receptor (cytoplasmic) tyrosine kinases, which are soluble, cytoplasmic kinases.
A reference proteome is a set of protein sequences derived from a complete proteome which constitutes a defined standard for a particular user community. Reference proteomes are manually defined according to a number of criteria. They cover the proteomes of well- studied model organisms and other proteomes of interest for biomedical and biotechnological research. Reference proteomes have been selected to provide broad coverage of the tree of life, and constitute a representative cross-section of the taxonomic diversity to be found within UniProtKB.