Fig. 8: Acute degradation of mAID:mTurq2:GKAP is followed by concomitant loss of synaptic PSD-95 and elevated levels of cytosolic PSD-95.

A A rat cortical neuron in culture co-expressing PSD-95:mCit (left) mAID:mTurq2:GKAP (middle) as well as OsTIR1-P2A-mCherry. B 5-Ph-IAA induced nearly complete loss of mAID:mTurq2:GKAP fluorescence, loss of PSD-95:mCit fluorescence from the same synapses and elevated levels of cytosolic PSD-95:mCit. Scale bar: 20 µm. C Changes in mAID:mTurq2:GKAP fluorescence measured at 24–78 synapses of each neuron tracked throughout the experiments (1723 synapses in total). Each thin gray line is the average normalized fluorescence measured for the synapses of one neuron (40 neurons from 5 experiments). Thick brown line is the population average. D PSD-95:mCit fluorescence measured at the same synapses and neurons of (C). Thick magenta line is the population average. E PSD-95:mCit fluorescence measured at 21–64 synapses of neurons positive for PSD-95:mCit and OsTIR1-P2A-mCherry but negative for mAID:mTurq2:GKAP (752 synapses in total). Each thin gray line is the average fluorescence measured for the synapses of one neuron (18 neurons from 5 experiments). Thick gray line is the population average. F Changes in cytosolic levels of PSD-95:mCit measured at the cell soma (31 neurons from 5 experiments). Dashed thick magenta line is the population average. G Changes in cytosolic PSD-95:mCit measured in the cell bodies of neurons positive for PSD-95:mCit and OsTIR1-P2A-mCherry but negative for mAID:mTurq2:GKAP (14 neurons from 5 experiments). Dashed thick gray line is the population average. H Pooled data. Dashed lines with filled triangles represent cytosolic PSD-95:mCit levels. Error bars are standard deviations. Tests for difference between PSD-95:mTurq2:mAID positive and negative cells – unpaired t-tests, without assuming equal variances; applied to data of last time points.