Pleckstrin Homology Domain Containing Family B, Member 1 (PLEKHB1)

The full-length human and mouse PHR1 proteins contain 243 amino acids and share 94% amino acid identity. PHR1 contains a pleckstrin homology (PH) domain at its N terminus and a 27-amino acid transmembrane segment at its C terminus. It also has several casein kinase II phosphorylation sites and a potential protein kinase C (PKC) phosphorylation site. Northern blot analysis of a human tissue panel revealed a major 2.0-kb transcript expressed at high levels in retina and brain, with much lower expression in several other tissues.The other 2 transcripts were prominently expressed in brain. Immunohistochemical localization and in situ hybridization of retina from several mammalian species localized PHR1 to the outer segment of both rods and cones and to the plasma membrane of retinal ganglion cells.