Inhomogeneity Based Characterization of Distribution Patterns on the Plasma Membrane

PLoS Comput Biol. 2016 Sep 7;12(9):e1005095. doi: 10.1371/journal.pcbi.1005095. eCollection 2016 Sep.

Abstract

Cell surface protein and lipid molecules are organized in various patterns: randomly, along gradients, or clustered when segregated into discrete micro- and nano-domains. Their distribution is tightly coupled to events such as polarization, endocytosis, and intracellular signaling, but challenging to quantify using traditional techniques. Here we present a novel approach to quantify the distribution of plasma membrane proteins and lipids. This approach describes spatial patterns in degrees of inhomogeneity and incorporates an intensity-based correction to analyze images with a wide range of resolutions; we have termed it Quantitative Analysis of the Spatial distributions in Images using Mosaic segmentation and Dual parameter Optimization in Histograms (QuASIMoDOH). We tested its applicability using simulated microscopy images and images acquired by widefield microscopy, total internal reflection microscopy, structured illumination microscopy, and photoactivated localization microscopy. We validated QuASIMoDOH, successfully quantifying the distribution of protein and lipid molecules detected with several labeling techniques, in different cell model systems. We also used this method to characterize the reorganization of cell surface lipids in response to disrupted endosomal trafficking and to detect dynamic changes in the global and local organization of epidermal growth factor receptors across the cell surface. Our findings demonstrate that QuASIMoDOH can be used to assess protein and lipid patterns, quantifying distribution changes and spatial reorganization at the cell surface. An ImageJ/Fiji plugin of this analysis tool is provided.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Algorithms
  • Animals
  • Cell Membrane / chemistry*
  • Cells, Cultured
  • Computational Biology / methods*
  • Image Processing, Computer-Assisted / methods*
  • Lipids / analysis*
  • Lipids / chemistry
  • Membrane Proteins / analysis*
  • Membrane Proteins / chemistry
  • Mice
  • Microscopy, Fluorescence
  • Software

Substances

  • Lipids
  • Membrane Proteins

Grants and funding

This work is financially supported by VIB, VIB Bio Imaging Core facility, the Hercules foundation for heavy infrastructure (Hercules AKUL058/HER/08/021, AKUL/09/037 and AKUL13/39 (the ISPAMM project)), KU Leuven (IDO/12/020), the federal government (IAP P7/16), SAO-FRMA (S#12012 & S#14017) and BRI-City of Hope Comprehensive Cancer Center. SM was supported by a grant from KU Leuven (CREA/12/22). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.