The N-terminal domain of human alpha-mannosidase contains a vacuolar targeting signal recognized by plant cells

?-Mannosidosis is a lysosomal storage disorder caused by mutations in the MAN2B1 clinical presentation of ?-mannosidosis is variable, but typically includes mental retardation, skeletal abnormalities and immune deficiency. The 200 a-a N-terminal part of the human a-mannosidase could contain a domain for vacuolar sorting in plant cells. Human a-mannosidase does not seem to follow the classical secretory patway route until vacuole.