Discs of mammalian rod photoreceptors form through the membrane evagination mechanism.

Published

Journal Article

Photoreceptor discs are membrane organelles harboring components of the visual signal transduction pathway. The mechanism by which discs form remains enigmatic and is the subject of a major controversy. Classical studies suggest that discs are formed as serial plasma membrane evaginations, whereas a recent alternative postulates that discs, at least in mammalian rods, are formed through intracellular vesicular fusion. We evaluated these models in mouse rods using methods that distinguish between the intracellular vesicular structures and plasma membrane folds independently of their appearance in electron micrographs. The first differentiated membranes exposed to the extracellular space from intracellular membranes; the second interrogated the orientation of protein molecules in new discs. Both approaches revealed that new discs are plasma membrane evaginations. We further demonstrated that vesiculation and plasma membrane enclosure at the site of new disc formation are artifacts of tissue fixation. These data indicate that all vertebrate photoreceptors use the evolutionary conserved membrane evagination mechanism to build their discs.

Full Text

Duke Authors

Cited Authors

  • Ding, J-D; Salinas, RY; Arshavsky, VY

Published Date

  • November 9, 2015

Published In

Volume / Issue

  • 211 / 3

Start / End Page

  • 495 - 502

PubMed ID

  • 26527746

Pubmed Central ID

  • 26527746

Electronic International Standard Serial Number (EISSN)

  • 1540-8140

Digital Object Identifier (DOI)

  • 10.1083/jcb.201508093

Language

  • eng

Conference Location

  • United States