Figure 4

Overexpression of SLMAP does not affect VSV-G transport from the ER. COS7 cells were co-transfected with 6Myc-SLMAP and ts045-VSV-G-GFP. When maintained at 40°C (a, d, g), the GFP-tagged viral glycoprotein was retained in the ER (d) and co-distributed with the Myc-labelled SLMAP protein (a). At 32°C, ts045-VSV-G-GFP exited the ER and was observed at perinuclear structures as well as at the cell periphery (e); whereas the 6Myc-SLMAP (b) appeared to remain in the ER. In cells incubated at reduced temperatures (15°C), the GFP-tagged viral glycoprotein is redistributed to perinuclear punctuate-like structures indicative of the ERGIC (f). The localization of the 6Myc-SLMAP (c) remained unaltered in these cells. Overlay of the anti-Myc and GFP signals is shown in g, h, and i.