What is the effect of defective or missing N-acetylglucosamine phosphotransferase on lysosomal protein sorting? Selected E. Nonfunctional lysosomal proteins accumulate in the lysosome. Answers: A. Lysosomal proteins are retained in the Golgi network. B. Lysosomal proteins are retained in the ER. C. Lysosomal proteins remain tightly bound to M6P receptors. D. Lysosomal proteins are secreted from the cell. E. Nonfunctional lysosomal proteins accumulate in the lysosome.