AGE

, Volume 33, Issue 4, pp 543–554

Tight binding of proteins to membranes from older human cells

  • Roger J. W. Truscott
  • Susana Comte-Walters
  • Zsolt Ablonczy
  • John H. Schwacke
  • Yoke Berry
  • Anastasia Korlimbinis
  • Michael G. Friedrich
  • Kevin L. Schey
Article

DOI: 10.1007/s11357-010-9198-9

Cite this article as:
Truscott, R.J.W., Comte-Walters, S., Ablonczy, Z. et al. AGE (2011) 33: 543. doi:10.1007/s11357-010-9198-9

Abstract

The lens is an ideal model system for the study of macromolecular aging and its consequences for cellular function, since there is no turnover of lens fibre cells. To examine biochemical processes that take place in the lens and that may also occur in other long-lived cells, membranes were isolated from defined regions of human lenses that are synthesised at different times during life, and assayed for the presence of tightly bound cytosolic proteins using quantitative iTRAQ proteomics technology. A majority of lens beta crystallins and all gamma crystallins became increasingly membrane bound with age, however, the chaperone proteins alpha A and alpha B crystallin, as well as the thermally-stable protein, βB2 crystallin, did not. Other proteins such as brain-associated signal protein 1 and paralemmin 1 became less tightly bound in the older regions of the lens. It is evident that protein–membrane interactions change significantly with age. Selected proteins that were formerly cytosolic become increasingly tightly bound to cell membranes with age and are not removed even by treatment with 7 M urea. It is likely that such processes reflect polypeptide denaturation over time and the untoward binding of proteins to membranes may alter membrane properties and contribute to impairment of communication between older cells.

Keywords

Human lensAgingProtein denaturationMembrane bindingLens barrier

Supplementary material

11357_2010_9198_Fig5_ESM.gif (94 kb)
Fig. 1

A heat map showing relative changes in major proteins that were tightly bound to lens membranes. Four geometric regions were dissected from each of two lenses aged 20 and 52. The average abundance in the young lens for each region was compared with the same region of the older lens. Red represents an overall relative protein decrease, blue an overall increase and white no change between the two age groups. Proteins with a spectral count less than 15 were not included in the data set. (GIF 94 kb)

11357_2010_9198_MOESM1_ESM.tif (442 kb)
High-resolution image (TIFF 441 kb)

Copyright information

© American Aging Association 2010

Authors and Affiliations

  • Roger J. W. Truscott
    • 1
  • Susana Comte-Walters
    • 2
  • Zsolt Ablonczy
    • 2
  • John H. Schwacke
    • 3
  • Yoke Berry
    • 4
  • Anastasia Korlimbinis
    • 1
  • Michael G. Friedrich
    • 1
  • Kevin L. Schey
    • 5
  1. 1.Save Sight InstituteSydney UniversitySydneyAustralia
  2. 2.Department of PharmacologyMedical University of South CarolinaCharlestonUSA
  3. 3.Department of BiochemistryMedical University of South CarolinaCharlestonUSA
  4. 4.School of ChemistryUniversity of WollongongWollongongAustralia
  5. 5.Mass Spectrometry Research CenterVanderbilt UniversityNashvilleUSA