Abstract
N-Linked glycans play important roles in the determination of glycoprotein fates in cells through interactions with a variety of intracellular lectins. Most of the intracellular lectins possess carbohydrate recognition domain, which is homologous to legume lectins or mannose 6-phosphate receptors (MPRs). These lectins are categorized as L-type or P-type lectins. Besides L-type lectins, recently accumulated frontal affinity chromatography and glycan microarray data have demonstrated that P-type lectins and the MPR homology (MRH) domain-containing proteins have distinct sugar-binding specificity profiles. Furthermore, newly emerged three-dimensional structural data have revealed sugar recognition mechanisms at an atomic level. This review summarizes the current state of knowledge of molecular and structural basis for sugar recognition by P-type lectins and MRH domain-containing proteins that control folding, transport, and degradation of N-linked glycoproteins in the secretory pathway.
