Topological analysis of the human beta2 adrenergic receptor expressed in Escherichia coli

We have investigated the topology of the
human jJ2-adrenerglc receptor expressed inEscherichia col,
using the genetic method described by B wth and coworkers.
We found that fusin with alkali phhatse beyond a
certain point on the human 2-adrenerglc receptor sequence
were assembled into the bacterial membrane with the same
topology as the human P2-adrenergic receptor in the mammalan
membrane. The pattern that might have been expected on
the basis of the topology of the human Az-adrenerglc receptor
in a membranes was not reflected in the levels of
alkaline phosphatase activity of the fusions occurring between
the N-terminal region and postions close to the second ex l
domain. Our data suggest that the correct positioning of the N
terminus of the receptor depends on the presence of its C-terminal
portions.