- Structure and function in rhodopsin: high-level expression of rhodopsin with restricted and homogeneous N-glycosylation by a tetracycline-inducible N-acetylglucosaminyltransferase I-negative HEK293S stable mammalian cell line. Reeves, P.J., Callewaert, N., Contreras, R., Khorana, H.G. Proc. Natl. Acad. Sci. U.S.A. (2002)