{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T04:33:56Z","timestamp":1787027636719,"version":"build-2736575974"},"reference-count":50,"publisher":"MDPI AG","issue":"4","license":[{"start":{"date-parts":[[2026,3,31]],"date-time":"2026-03-31T00:00:00Z","timestamp":1774915200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100000038","name":"Natural Sciences and Engineering Research Council of Canada","doi-asserted-by":"publisher","award":["RGPIN-2023-03975"],"award-info":[{"award-number":["RGPIN-2023-03975"]}],"id":[{"id":"10.13039\/501100000038","id-type":"DOI","asserted-by":"publisher"}]},{"award":["RGPIN-2023-03975"],"award-info":[{"award-number":["RGPIN-2023-03975"]}],"id":[{"id":"https:\/\/ror.org\/01h531d29","id-type":"ROR","asserted-by":"publisher"}]},{"DOI":"10.13039\/100000897","name":"Cystic Fibrosis Foundation","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100000897","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Biomolecules"],"abstract":"<jats:p>Current models of the cell membrane assume a heterogenous environment such as sphingomyelin and cholesterol-enriched nano- and microdomains, which are thought to functionally sequester proteins. Besides lipid-ordered domains, membrane proteins can interact with protein complexes by transient binding\u2014necessary for their functional role. Here, we show that an extension of k-space Image Correlation Spectroscopy applied to standard fluorescence microscopy image time series can be used to characterize the protein confinement in heterogeneous membranes. To validate this method, we simulated confined diffusion of tracer particles in a system of static microdomains where we varied the domain size, domain density, confinement probability and diffusion coefficients of tracer particles. We show how the kICS correlation function changes with these parameters and gives rise to emergent properties of the system such as apparent domain sizes and characteristic diffusion coefficients. As a validity check, we apply this analysis to study the dynamics of lipid domain-associated glycosylphosphatidyl inositol (GPI)-anchored proteins labeled by green fluorescent proteins (GPI-GFP) in intact COS-7 cell membranes, and upon domain-disrupting enzyme treatments.<\/jats:p>","DOI":"10.3390\/biom16040519","type":"journal-article","created":{"date-parts":[[2026,4,2]],"date-time":"2026-04-02T09:26:12Z","timestamp":1775121972000},"page":"519","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Measurement of Protein Transport in Heterogeneous Environments Using Confinement k-Space Image Correlation Spectroscopy"],"prefix":"10.3390","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3733-0890","authenticated-orcid":false,"given":"Elvis","family":"Pand\u017ei\u0107","sequence":"first","affiliation":[{"name":"Katharina Gaus Light Microscopy Facility, Mark Wainwright Analytical Center, UNSW Sydney, Sydney, NSW 2052, Australia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9080-2039","authenticated-orcid":false,"given":"John W.","family":"Hanrahan","sequence":"additional","affiliation":[{"name":"Department of Physiology, McGill University, Montreal, QC H0H H9Z, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7069-8836","authenticated-orcid":false,"given":"Asmahan","family":"Abu-Arish","sequence":"additional","affiliation":[{"name":"Department of Anatomy, Physiology and Pharmacology, University of Seskatchewan, Saskatoon, SK S7N 5E5, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5732-2858","authenticated-orcid":false,"given":"Paul W.","family":"Wiseman","sequence":"additional","affiliation":[{"name":"Physics and Chemistry Departments, McGill University, Montreal, QC H3A 0C8, Canada"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,3,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"569","DOI":"10.1038\/42408","article-title":"Functional rafts in cell membranes","volume":"387","author":"Simons","year":"1997","journal-title":"Nature"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"6197","DOI":"10.1021\/bi00417a001","article-title":"Lipid sorting in epithelial cells","volume":"27","author":"Simons","year":"1988","journal-title":"Biochemistry"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"577","DOI":"10.1016\/S0092-8674(04)00167-9","article-title":"Nanoscale Organization of multiple GPI-anchored proteins in living cell membranes","volume":"116","author":"Sharma","year":"2004","journal-title":"Cell"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"213","DOI":"10.1111\/j.1600-0854.2004.0178.x","article-title":"Molecular dynamics and interactions for creation of stimulation induced stabilized rafts from small unstable steady-state rafts","volume":"5","author":"Suzuki","year":"2004","journal-title":"Traffic"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"774","DOI":"10.1038\/nchembio.1028","article-title":"Transient GPI-anchored protein homodimers are units for raft organization and function","volume":"8","author":"Suzuki","year":"2012","journal-title":"Nat. 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