ABSTRACT
One-third of all newly synthesized proteins are cotranslationally inserted into the endoplasmic reticulum (ER) where they are folded, modi ed, and subjected to quality control prior to secretion or transport to various intracellular organelles. During translocation, a majority of these proteins are N-glycosylated by the addition of a 14-saccharide core glycan at conserved Asn-X-Ser/Thr consensus sequences [1]. N-linked glycans are important determinants of protein recognition and modi cation involving intracellular lectins at various steps along the secretory pathway. The rst lectins encountered by a newly synthesized glycoprotein are calnexin and calreticulin, two ER-localized proteins that support protein folding and quality control [2]. Correctly folded glycoproteins can then be captured by members of an additional class of animal lectins termed L-type lectins [3]. These lectins are characterized by a luminal carbohydrate recognition domain (CRD) that corresponds to the single-folded domain of soluble lectins found in the seeds of leguminous plants [4,5].
