Supplementary Figure 4: Optimization of Magneto1.0 by improving cellular trafficking.
From: Genetically targeted magnetic control of the nervous system
(a-e) HEK293 cells transfected with mCherry-fused variants of Magneto1.0 with combinations of various inwardly rectifying K+ channel 2.1 (Kir2.1) trafficking signals. (a) Magneto1.0-mCherry shows diffuse cellular localization, poor membrane expression, and poor transfection efficiency. (b) Addition of ER export signal from Kir2.1 to C-terminus of Magneto1.0-mCherry peptide partially improves Magneto expression. (c) Addition of Kir2.1 membrane trafficking signal (TS) significantly improves membrane expression of Magneto. (d) Dual addition of membrane trafficking and ER export signals improves expression relative to Magneto1.0 but not relative to a single membrane trafficking signal. (e) Tandem Kir2.1 membrane trafficking/ER export signals on Magneto1.0 C-terminus improves expression but not relative to c. n=2 coverslips and >100 cells analyzed per trafficking modification examined.
