December 2002
Volume 43, Issue 13
ARVO Annual Meeting Abstract  |   December 2002
Crx-Independent Expression of Rhodopsin Kinase (Rk)
Author Affiliations & Notes
  • JE Young
    SUNY Buffalo Buffalo NY
  • S Finnegan
    SUNY Buffalo Buffalo NY
  • K Gross
    Molecular Biology Roswell Park Cancer Institute Buffalo NY
  • D Higgins
    SUNY Buffalo Buffalo NY
  • SC Khani
    SUNY Buffalo Buffalo NY
  • Footnotes
    Commercial Relationships   J.E. Young, None; S. Finnegan, None; K. Gross, None; D. Higgins, None; S.C. Khani, None. Grant Identification: Support: Alexandrine and Alexander L. Sinsheimer Fund
Investigative Ophthalmology & Visual Science December 2002, Vol.43, 1432. doi:
  • Views
  • Share
  • Tools
    • Alerts
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      JE Young, S Finnegan, K Gross, D Higgins, SC Khani; Crx-Independent Expression of Rhodopsin Kinase (Rk) . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1432.

      Download citation file:

      © ARVO (1962-2015); The Authors (2016-present)

  • Supplements

Abstract: : Purpose: The homeodomain transcription factor Crx has been shown to play an important role in the regulation of many photoreceptor-specific genes. The expression of some photoreceptor-specific genes, however, such as Rk, appear unaffected by the targeted disruption of the Crx gene. Our goal is to explore the mechanisms underlying Crx-independent photoreceptor-specific expression of Rk. Methods: RACE was used to amplify the previously uncharacterized leader sequence of Rk mRNA from C57BL/J mouse retina. The amplified cDNAs were cloned and sequenced and the promoter regions upstream of the mouse and human Rk gene were compared by BLAST algorithm. Conserved sequences within the 5' flanking region were fused upstream of the luciferase and LacZ reporter genes and used to transfect WERI retinoblastoma and dissociated human retinal cells in culture. The homeobox-binding site within the Rk promoter region was disrupted using site-directed mutagenesis in some of the constructs. The interaction of nuclear factors with the promoter sequences including the homeodomain-binding site was examined using gel retardation assay with nuclear extracts from normal BL/J and Crx-deficient mice. Results: Comparison of the upstream promoter region of both human and mouse rhodopsin kinase reveals ∼200-bp island of sequence homology containing a homeobox binding sequence CTAAT. Disruption of the homeobox sequence led to substantial decrease in reporter gene expression but did not abolish the activity of the promoter. No differences were observed in gel retardation assays when comparing the binding patterns of normal and Crx-/- mouse retinal nuclear proteins to the Rk homeobox-binding site. Conclusion: Our findings suggest that the mouse and human Rk genes share a highly conserved proximal promoter which is likely to be responsible for the appropriate developmental and photoreceptor cell-specific regulation of the gene. The proximal promoters in both genes contain a homeodomain-binding site whose disruption reduces but does not abolish promoter activity. The binding patterns of the promoter sequences to the nuclear proteins suggests a role for homeodomain transcription factor other than Crx in the regulation of Rk gene.

Keywords: 417 gene/expression • 560 retinal culture • 605 transcription factors 

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.