LOXL1 folding in exfoliation glaucoma

Audrey M. Bernstein, Robert Ritch, J. Mario Wolosin

Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review

12 Scopus citations

Abstract

Exfoliation syndrome (XFS) is an age-related disease defined by the deposition of aggregated fibrous material (XFM) in the peri-cellular space. Principal morbidity occurs in the eye, where XFM accumulates on the anterior ocular tissues. GWAS have found that certain genetic variants of lysyl oxidase-like 1 (LOXL1), a matrix cross-linking enzyme that is required for elastic fiber formation confer risk for the development of XFS, but are not a single causative factor as many genetically affected individuals do not develop XFS or subsequent glaucoma (XFG). We have found that XFG cells display defects in lysosomes, microtubules, autophagy, and mitochondria resembling defects found in cells from age-related syndromes, such as the main neurodegenerative diseases. In the majority of these diseases, the determining cellular factor is a protein containing intrinsically disordered regions (IDRs) and displaying a high propensity for aggregation. We have found that in XFG patient-derived cells, LOXL1 protein is actively subjected to autophagic clearance, suggesting that LOXL1 is undergoing aggregation. In silico analysis demonstrates that LOXL1's first 369 aa constitute an IDR with the highest disorder probability peak centering around the known risk positions. Experimentally, we have found over-expression of either unmodified LOXL1 or fluorescent chimeras preserving the well-structured N-terminus cause copious intracellular aggregation and that aggregation wanes when the high IDR peaks are deleted. Overall, our work suggests that XFS/G results from the aggregation of the LOXL1 protein coupled with a reduction of cellular proteostasis capabilities in aging, resulting in a chronic build-up of LOXL1-containing protein aggregates.

Original languageEnglish
Title of host publicationProtein Misfolding
EditorsRossen Donev
PublisherAcademic Press Inc.
Pages273-288
Number of pages16
ISBN (Print)9780128177501
DOIs
StatePublished - 2019

Publication series

NameAdvances in Protein Chemistry and Structural Biology
Volume118
ISSN (Print)1876-1623
ISSN (Electronic)1876-1631

Keywords

  • Aggregopathy
  • Autophagy
  • Glaucoma
  • Intrinsically disordered regions
  • LOXL1

Fingerprint

Dive into the research topics of 'LOXL1 folding in exfoliation glaucoma'. Together they form a unique fingerprint.

Cite this