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Overexpression of ROM-1 in the Cone-Dominant Retina

  • Dibyendu Chakraborty
  • Shannon M. Conley
  • Zack Nash
  • Xi-Qin Ding
  • Muna I. NaashEmail author
Conference paper
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 723)

Abstract

ROM-1 (rod outer segment membrane protein-1) is a tetraspanin protein present in the outer segment (OS) rims of rod and cone photoreceptors. It shares many common features with other tetraspanins, including a large intradiscal loop which contains several cysteines. This loop enables ROM-1 to associate with its homologue retinal degeneration slow (RDS) to form hetero-tetramers and hetero-octamers. Although large RDS homo-oligomers are required for building and maintaining the rim region of rod discs and cone lamellae, the function of ROM-1 is less clear. ROM-1 is not necessary for disc morphogenesis but is required for fine tuning OS disc size and structure. Furthermore, the role of ROM-1 has not been well studied in cone photoreceptors. To help alleviate this knowledge gap, we overexpressed ROM-1 via transgenesis in the cone-dominant nrl −/− mouse retina. We show that ∼20% overexpression of ROM-1 results in vacuoles in the cone OSs and significant reductions in photopic electroretinogram responses. These results indicate that overexpression of ROM-1 is harmful to cone OSs. We hypothesize that overexpression of ROM-1 alters the normal balance between RDS homo-oligomers and RDS/ROM-1 heteromeric complexes, resulting in insufficient or abnormal higher-order RDS homo-oligomers for the maintenance of proper OS structure and function.

Keywords

ROM-1 RDS Cone Mouse models Nrl Transgene 

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Copyright information

© Springer Science+Business Media, LLC 2012

Authors and Affiliations

  • Dibyendu Chakraborty
    • 1
  • Shannon M. Conley
    • 1
  • Zack Nash
    • 1
  • Xi-Qin Ding
    • 1
  • Muna I. Naash
    • 1
    Email author
  1. 1.Department of Cell BiologyUniversity of Oklahoma Health Sciences CenterOklahoma CityUSA

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