Table 1 Phenotypic categorization of SI mutants
From: The multiple roles of sucrase-isomaltase in the intestinal physiology
Phenotype of SI mutants | Transport and function |
|---|---|
I | Blocked in the ER, enzymatically inactive |
II | Blocked in the ER, ER-Golgi intermediate compartment, and cis-Golgi, inactive |
III | Normal intracellular protein transport but absent activities |
IV | Sorting defects, enzymatically active |
V | Intracellular proteolytic cleavage and degradation of sucrase, normal transport and partial activity |
VI | Intracellular proteolytic cleavage and secretion of SI, complete activity |
VII | Altered trafficking and increased turnover rate, partially active |