FIGURE 4.

Separation of aquaporin tetramers by column size exclusion chromatography. A, size-fractionated plasma membrane proteins with a molecular mass larger than 80 kDa from yeast strains expressing NtAQP1 fused to a YFP C-terminal region (Nt-YC, diamonds) or NtPIP2.1 (PIP2.1, triangles). B, shown as described in A, but yeast strains expressing NtAQP1 were fused to a YFP C-terminal region, and NtPIP2.1 was probed with a NtAQP1 (Nt Hetero, diamonds) or a NtPIP2;1-specific antibody (PIP2;1 Hetero, triangles). For illustration of protein distribution a free hand trend line was added (NtAQP1, black; NtPIP2;1, gray). Data refer to relative signal distribution (means ± S.E.). rel., relative.