ZFIN ID: ZDB-PUB-091023-50
Restricted localization of ponli, a novel zebrafish MAGUK-family protein, to the inner segment interface areas between green, red, and blue cones
Zou, J., Yang, X., and Wei, X.
Date: 2010
Source: Investigative ophthalmology & visual science   51(3): 1738-1746 (Journal)
Registered Authors: Wei, Xiangyun
Keywords: none
MeSH Terms:
  • Amino Acid Sequence
  • Animals
  • Blotting, Western
  • Cloning, Molecular
  • Guanylate Cyclase/genetics
  • Guanylate Cyclase/metabolism*
  • Membrane Proteins/genetics
  • Membrane Proteins/metabolism*
  • Microscopy, Immunoelectron
  • Molecular Sequence Data
  • Nucleic Acid Amplification Techniques
  • Retinal Photoreceptor Cell Inner Segment/metabolism*
  • Reverse Transcriptase Polymerase Chain Reaction
  • Rod Opsins/metabolism*
  • Sequence Homology, Amino Acid
  • Zebrafish
  • Zebrafish Proteins/genetics
  • Zebrafish Proteins/metabolism*
PubMed: 19834027 Full text @ Invest. Ophthalmol. Vis. Sci.
PURPOSE: The inner segments (IS) of the photoreceptors in vertebrates are enriched with polarity scaffold proteins, which maintain the integrity of many tissues by mediating cell-cell adhesion either directly or indirectly. The formation of photoreceptor mosaics may require differential adhesion among different types of photoreceptors. It is unknown if any polarity proteins are selectively expressed in certain photoreceptors to mediate differential intercellular adhesion, which may be important for photoreceptor patterning. This study was undertaken to identify such polarity proteins. METHODS: To identify novel MAGUK-family (Membrane Associated Guanylate Kinase) proteins that are similar to Nagie oko (Nok), we performed BLAST searches of the zebrafish genome with the Nok amino acid sequence as the query. The coding sequence of one of the identified genes was obtained and verified through RT-PCR and RACE (Rapid Amplification of cDNA Ends). Its protein expression patterns were examined by immunomicroscopy and Western blotting. Morpholino knockdown technology was used for loss-of-function analyses. RESULTS: We cloned a novel nok homolog and designated it photoreceptor-layer-nok-like (ponli). Unlike Nok, which is expressed broadly, Ponli is only expressed at the interface areas between the IS of the green, red, and blue cones in differentiated zebrafish retina. CONCLUSION: Ponli is the first identified polarity protein that is not expressed in all types of photoreceptors. Ponli's selective distribution stimulates future investigations on its functions for photoreceptor mosaic formation.