VNUT is expressed in isolated ATII cells and localized on the LB membrane. (A) Western blot of VNUT from ATII cells freshly isolated and 48 h after isolation confirms that expression of VNUT is not altered in cultured cells. (B) VNUT (green) is primarily localized on LB membranes (arrowheads) as detected by indirect immunofluorescence and confirmed by colocalization with P180 lamellar body protein (red, α-ABCa3). Asterisks denote nuclei of individual primary ATII cells. Bar: 10 µm; (inset) 2 µm. (C) VNUT-GFP (green) localizes to the membrane of LBs (LTR, red) in primary ATII cells. Asterisk denotes nuclei of primary ATII cell. Bar: 10 µm; (inset) 2 µm.