Fig. 4: Plasma membrane targeting of BRI1 is impaired in sun3/4/5.
From: POD1-SUN-CRT3 chaperone complex guards the ER sorting of LRR receptor kinases in Arabidopsis
a POD1 interacts with CRT3 by Co-IP assay with Arabidopsis protoplasts. b SUN4 interacts with CRT3 independently of glycosylation. The protoplasts were treated with 5 mΜ Tm to inhibit the protein glycosylation after transformation with the indicated plasmids. The shifted bands indicated that the glycosylation of SUN4 was inhibited. CRT2 was used as a negative control. c The protein structure of CRT3 and the constructs used in d. d The interaction between SUN4 and CRT3 depends on the lectin domain. e, f Confocal image of BRI1-GFP in the WT (e) and sun3/4/5 (f) root cells. Scale bar, 10 μm. g Confocal image of Venus-PIP2;7 in the WT and sun3/4/5 root cells. Scale bar, 10 μm. h LysoTracker red staining of BRI1-GFP in sun3/4/5. Left panel, GFP channel; middle panel, LysoTracker red staining; right panel, merged image. Arrow, vacuole (v) and the plasma membrane (pm). Bar, 5 μm. i Rhodamine B hexyl ester staining of the ER in roots of BRI1-GFP; sun3/4/5. Left panel, GFP channel; middle panel, Rhodamine B hexyl ester staining; right panel, merged image. Bar, 5 μm. j Loss of SUN3, SUN4 and SUN5 aggravates the growth defect of bri1-9 and bri1-5. 3 (a, b, d) and 6 (e–i) independent biological experiments were repeated.
