A modified FCCS procedure applied to Ly49A-MHC class Icis-interaction studies in cell membranes
2011 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 101, no 5, 1257-1269 p.Article in journal (Refereed) Published
The activity of natural killer (NK) cells is regulated by a fine-tuned balance between activating and inhibitory receptors. Dual-color fluorescence cross-correlation spectroscopy (FCCS) was used to directly demonstrate a so-called cis-interaction between a member of the inhibitory NK cell receptor family Ly49 (Ly49A), and its ligand, the major histocompatibility complex (MHC) class I, within the plasma membrane of the same cell. By a refined FCCS model, calibrated by positive and negative control experiments on cells from the same lymphoid cell line, concentrations and diffusion coefficients of free and interacting proteins could be determined on a collection of cells. Using the intrinsic intercellular variation of their expression levels for titration, it was found that the fraction of Ly49A receptors bound in cis increase with increasing amounts of MHC class I ligand. This increase shows a tendency to be more abrupt than for a diffusion limited three dimensional bimolecular reaction, which most likely reflects the two-dimensional confinement of the reaction. For the Ly49A- MHC class I interaction it indicates that within a critical concentration range the local concentration level of MHC class I can provide a distinct regulation mechanism of the NK cell activity.
Place, publisher, year, edition, pages
Elsevier, 2011. Vol. 101, no 5, 1257-1269 p.
FLUORESCENCE CORRELATION SPECTROSCOPY, CROSS-CORRELATION SPECTROSCOPY, PROTEIN-PROTEIN INTERACTIONS, LIVE CELLS, RECEPTOR, FLUCTUATIONS, ACTIVATION, EXPRESSION, SURFACE, VIVO
Research subject Biological Physics
IdentifiersURN: urn:nbn:se:kth:diva-34018DOI: 10.1016/j.bpj.2011.06.057ISI: 000294653800028PubMedID: 21889464ScopusID: 2-s2.0-80052506011OAI: oai:DiVA.org:kth-34018DiVA: diva2:418571
FunderSwedish Research Council, VR-NT 2009-3134Swedish Foundation for Strategic Research
QC 201406092011-05-232011-05-232016-06-01Bibliographically approved