Figure 1. Surface GMRβ molecules form ligand-independent nano-scale clusters, some of which are colocalized with CCPs. (A) TIRF and dSTORM images of HeLa cells transiently co-expressing GMRα-CFP (not shown) and GMRβ (red, labeled by antibody, see Materials and Methods) in medium containing or not containing GM-CSF (± GM). Endogenous CHC was stained by specific antibody (green). (B) The size of a GMRβ cluster shown in (A) was calculated by the pair distance analysis (see Materials and Methods). Shown here are two representative histograms of distances of GMRβ pairs within a GMRβ cluster. (C) Estimated cluster size and number of GMRβ or CHC molecules in each cluster shown in (A). Data are presented as mean ± SD, n = 100. (D) Images of endogenous surface GMRβ in TF1 cells taken by TIRF, Epifluorescence (Epi), or differential interference contrast (DIC) microscopy.