Calcium-dependent cell-adhesion protein. Essential for maintenance of normal retinal and cochlear function.
Subcellular locations: Cell membrane
Efficient localization to the plasma membrane requires the presence of LHFPL5.
Subcellular locations: Secreted
Expressed in brain, lung, kidney, spleen and testis. Found also in the inner and outer synaptic layers, and the nerve fiber layer in adult and fetal retinas. Found in the supporting cells, outer sulcus cells and spiral ganglion of fetal cochlea. Expressed in cytotoxic tumor-derived T- and NK-cell lines as well as biopsies of nasal NK/T-cell lymphomas. Not detected in normal or in vitro activated peripheral blood cells, CD4 or CD8 lymphocytes or NK cells. Isoform 3 is expressed in brain, heart, cerebellum and kidney. CD1 isoforms, such as isoform 1, have a limited pattern of expression and is detected in testis, retina and cochlea. CD2 isoforms, such as isoforms 4 and 5, are expressed in heart, kidney, thymus, spleen, testis, retina and cochlea. CD3 isoforms, such as isoform 6, are widely expressed.