Fig. 7: Effect of SAP97/hDLG isoform compositionality on nanoscale condensates.
From: Nanoscale regulation of Ca2+ dependent phase transitions and real-time dynamics of SAP97/hDLG
A Ectopic expression of I3-hDLG::mEos in hippocampal pyramidal neurons (DIV-14) shows distinct localization in dendritic shafts and is enriched in morphologically characterized spines (epifluorescence). Super resolution imaging confirms nanoscale condensates (super resolved) formed in dendrites and synaptic compartments (overlay). Scalebar indicates 5 µm. Insets of super resolved images (red regions, super resolved image) are presented to illustrate heterogeneity in nanoscale condensates of SAP97/hDLG in spines and dendritic shafts (1,2,3,4). Scalebar indicates 1.5 µm. B Left panel indicates association of SAP97/hDLG condensates with a single postsynaptic density. Postsynaptic density protein PSD95 (Magenta) was identified by semiautomated analysis and its overlap with the nanoscale distribution of endogenous SAP97/hDLG (Green) is presented in white. Scalebar indicates 0.5 µm. Right panel indicates the localization of SAP97/hDLG nanoscale condensates with respect to the nearest identified postsynaptic density (black region). Pseudo color scalebar in all microscopy images represents normalized intensity from maximum to minimum (black to white). C Plot of ∆G, derived from the probability density function, with number of molecules per cluster (n) indicates the combined molecular fingerprints of critical cluster radius and nucleation barrier between different conditions of SAP97/hDLG modulation in Neuro-2a cells and hippocampal pyramidal neurons. D The critical cluster radii of SAP97/hDLG remained similar between Neuro-2a cells ectopically expressing I2 and I3 isoform, while it was significantly different between untransfected neurons and Neuro-2a cells. E The nucleation barrier of SAP97/hDLG remained similar between Neuro-2a cells expressing the I3 isoform of SAP97/hDLG and untransfected neurons, while it significantly differed between I3 and I2 isoforms and untransfected Neuro-2a cells. The box represents 25% percentile, median and 75% percentile (Source Data), while the whiskers represents the minimum and maximum values (Source Data). N = 9 cells for each condition. Data are cumulated from three experiments. *p < 0.05, **p < 0.01, ****p < 0.0001 (Supplementary Table 6). Source data are provided as Source Data file.
