MAP1B Interaction with the FW Domain of the Autophagic Receptor Nbr1 Facilitates Its Association to the Microtubule Network

Figure 6

Nbr1 and MAP1B colocalise in discrete perinuclear vesicles upon induction of autophagy. PC12 cells were treated with DMSO, Bafilomycin or starved then fixed and stained with antibodies against the indicated proteins. Under basal conditions (A) or when autophagic degradation is blocked by Bafilomycin A1 treatment (B), very little or no colocalisation was observed between Nbr1 and MAP1B. When cells were starved to induce autophagy (C) MAP1B and Nbr1 colocalise in distinct perinuclear vesicles which are also positive for p62 (D) but are largely negative for ULK1 (E), ubiquitin (F), and EEA1 (G). Upon depolymerisation of the microtubule network and subsequent induction of autophagy by starvation, MAP1B no longer colocalised in distinct perinuclear vesicles with Nbr1 (H). Antibodies used: anti-Nbr1 (abcam), anti-MAP1B (N19, Santa Cruz), anti-p62 (M. Gautel, KCL), anti-ULKl (Sigma), anti-ubiquitin (Ub) (Sigma), and anti-EEAl (Cell Signaling). Scale bar; 10 μm.