ZFIN ID: ZDB-PUB-000505-1
Cloning and tissue localization of a novel zebrafish RdgB homolog that lacks a phospholipid transfer domain
Elagin, V.A., Elagina, R.B., Doro, C.J., Vihtelic, T.S., and Hyde, D.R.
Date: 2000
Source: Visual neuroscience   17(2): 303-311 (Journal)
Registered Authors: Hyde, David R., Vihtelic, Thomas
Keywords: retinal degeneration; RdgB; phosphatidylinositol transfer protein; zebrafish; Drosophila; cone photoreceptor
MeSH Terms:
  • Amino Acid Sequence
  • Animals
  • Brain/metabolism
  • Carrier Proteins/genetics*
  • Carrier Proteins/metabolism
  • Cloning, Molecular
  • DNA Primers/chemistry
  • Drosophila/genetics
  • Drosophila Proteins*
  • Electroretinography
  • Eye Proteins*
  • Fluorescent Antibody Technique, Indirect
  • Gene Expression
  • Membrane Proteins/genetics*
  • Membrane Proteins/metabolism*
  • Molecular Sequence Data
  • Phospholipid Transfer Proteins
  • Phospholipids/metabolism*
  • Retina/metabolism*
  • Retinal Degeneration/genetics*
  • Retinal Degeneration/metabolism
  • Retinal Degeneration/prevention & control
  • Sequence Homology, Amino Acid
  • Zebrafish
PubMed: 10824684 Full text @ Vis. Neurosci.
The retinal degeneration B (RdgB) protein family is characterized by an amino-terminal phosphatidylinositol transfer protein (PITP) domain, several hydrophobic domains, and a highly conserved carboxyl terminus. We identified a zebrafish RdgB homolog (pl-RdgB)that lacks the amino-terminal PITP domain, while retaining over 45% amino acid identity with the two mouse RdgB proteins (M-RdgB1 and M-RdgB2). Unlike the widespread retinal expression observed for other vertebrate RdgB homologs, pl-RdgB is restricted in the retina to the cone cell inner segments. The pl-RdgB protein is also expressed in the brain, although its distribution is different than the other RdgB homologs. Analogous to M-RdgB2, pl-RdgB protein is extracted from a retinal homogenate by guanidine and not by Triton X-100. Thus, pl-RdgB and likely all the identified RdgB homologs are not integral membrane proteins, but may associate with the membrane through protein-protein interactions. While expression of either murine RdgB homolog restored the defective light response and prevented retinal degeneration in rdgB mutant flies, expressing zebrafish pl-RdgB in Drosophila rdgB2 null mutants slowed retinal degeneration without restoring the electrophysiological light response. Thus, pl-RdgB may define a previously unrecognized protein family, which includes the other RdgB homologs, that act through a protein complex to maintain photoreceptor viability.