Evectins: vesicular proteins that carry a pleckstrin homology domain and localize to post-Golgi membranes.
We have identified two vesicular proteins, designated evectin (evt)-1 and -2. These proteins are approximately 25 kDa in molecular mass, lack a cleaved N-terminal signal sequence, and appear to be inserted into membranes through a C-terminal hydrophobic anchor. They also carry a pleckstrin homology domain at their N termini, which potentially couples them to signal transduction pathways that result in the production of lipid second messengers. evt-1 is specific to the nervous system, where it is expressed in photoreceptors and myelinating glia, polarized cell types in which plasma membrane biosynthesis is prodigious and regulated; in contrast, evt-2 is widely expressed in both neural and nonneural tissues. In photoreceptors, evt-1 localizes to rhodopsin-bearing membranes of the post-Golgi, an important transport compartment for which specific molecular markers have heretofore been lacking. The structure and subcellular distribution of evt-1 strongly implicate this protein as a mediator of post-Golgi trafficking in cells that produce large membrane-rich organelles. Its restricted cellular distribution and genetic locus make it a candidate gene for the inherited human retinopathy autosomal dominant familial exudative vitreoretinopathy and suggest that it also may be a susceptibility gene for multiple sclerosis.
Krappa
R
R
Molecular Neurobiology Laboratory, The Salk Institute, La Jolla, CA 92037, USA.
Nguyen
A
A
Burrola
P
P
Deretic
D
D
Lemke
G
G
D000595:Amino Acid Sequence; D000818:Animals; D002490:Central Nervous System / Q000378:metabolism*; D003001:Cloning, Molecular; D006056:Golgi Apparatus / Q000378:metabolism*; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000032:analysis / Q000737:chemistry / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D008970:Molecular Weight; D005810:Multigene Family; D009928:Organ Specificity; D010786:Photoreceptor Cells / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis; D011898:Ranidae; D051381:Rats; D011994:Recombinant Proteins / Q000032:analysis / Q000096:biosynthesis; D012160:Retina / Q000378:metabolism; D015290:Second Messenger Systems; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D014158:Transcription, Genetic; D018909:src Homology Domains
D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C417163:PLEKHB1 protein, human; C118742:PLEKHB2 protein, human; C485943:Plekhb1 protein, mouse; C485942:Plekhb1 protein, rat; C485570:Plekhb2 protein, mouse; D012333:RNA, Messenger; D011994:Recombinant Proteins