Impact of Hybrid and Complex N-Glycans on Cell Surface Targeting of the Endogenous Chloride Cotransporter Slc12a2

Figure 4

A small proportion of total NKCC1 locates in the plasma membrane. (a) Representative NKCC1 immunoblot of equal amounts of total protein extracts and plasma membrane biotinylated fractions obtained from COS7 cells growing under normal conditions. Shown are bands of expected sizes of NKCC1, that is, ~170 kDa and ~130 kDa, in total cellular extracts and in biotinylated plasma membrane fractions. Protein expression of cytosolic GAPDH was used as a loading control for total protein lysates and to assess the purity of biotinylated plasma membrane fractions. (b) Densitometry analysis of immunoblots showing estimated levels of the two main immunobands of NKCC1: core/high-mannose ~130 kDa (green bars) and complex/hybrid ~170 kDa (red bars) in total lysates or biotinylated plasma membrane fractions. Data is expressed as the mean ± SEM (). (c) Pie-chart representation of the estimated, relative contribution of total NKCC1 to the plasma membrane.

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