Suppose you wish to determine if the small subunit of the Na

Suppose you wish to determine if the small subunit of the Na+K+ATPase is a transmembrane protein, with domains that extend out from the membrane on both sides. Design an experiment using a protease and cultured neurons to determine if this is the case. What result would you expect if the protein only extends out on the external side of the membrane.

Solution

If the protein here in this case; the small subunit of the Na+K+ATPase extends out on the external side of the membrane; it will lose its function only when we supply the protease in the medium of the cells. However if the small subunit of the Na+K+ATPase is a transmembrane protein, with domains that extend out from the membrane on both sides; the function of the small subunit of the Na+K+ATPase will be lost by the increase in the concentration of the protease intracellular as well as extracellular in the Phagosome by the up regulation of the gene coding for it.