Malectin (MLEC)

Malectin is an endoplasmic reticulum (ER)-localized, type I membrane-anchored carbohydrate-binding protein that specifically recognizes di-glucosylated N-glycans (Glc₂Man₉GlcNAc₂), a transient glycan generated early during protein N-glycosylation[1][3]. It contains a unique carbohydrate-binding domain structurally similar to prokaryotic carbohydrate-binding modules (CBMs), but with additional structural features that distinguish it as a unique lectin family member[3]. Malectin binds preferentially to misfolded glycoproteins through their N-glycan signatures and, via interaction with ribophorin I (a component of the oligosaccharyltransferase complex), retains aberrantly folded proteins in the ER and directs them for ER-associated degradation, a process critical for maintaining proteostasis[1][3]. Polymorphisms in the MLEC gene are linked to altered immune cell polarization and have been implicated in the pathogenesis of cerebral palsy, suggesting roles in immune homeostasis and inflammatory disease[1]. However, it is not currently recognized as a direct therapeutic target or receptor for drugs; no approved drugs or investigational therapeutics are known to specifically modulate malectin activity, nor is it established as a clinical biomarker or associated with specific safety concerns.

Other names

MalectinKIAA0152oligosaccharyltransferase complex subunit (non-catalytic)MLEC