title: Lectins and protein traffic early in the secretory pathway.
abstract: Lectins of the early secretory pathway are involved in selective transport of newly synthesized glycoproteins from the endoplasmic reticulum (ER) to the ER-Golgi intermediate compartment (ERGIC). The most prominent cycling lectin is the mannose-binding type I membrane protein ERGIC-53 (ERGIC protein of 53 kDa), a marker for the ERGIC, which functions as a cargo receptor to facilitate export of an increasing number of glycoproteins with different characteristics from the ER. Two ERGIC-53-related proteins, VIP36 (vesicular integral membrane protein 36) and a novel ERGIC-53-like protein, ERGL, are also found in the early secretory pathway. ERGL may act as a regulator of ERGIC-53. Studies of ERGIC-53 continue to provide new insights into the organization and dynamics of the early secretory pathway. Analysis of the cycling of ERGIC-53 uncovered a complex interplay of trafficking signals and revealed novel cytoplasmic ER-export motifs that interact with COP-II coat proteins. These motifs are common to type I and polytopic membrane proteins including presenilin 1 and presenilin 2. The results support the notion that protein export from the ER is selective.
authors.affiliation: Biozentrum, Klingelbergstrasse 70, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland. hans-peter.hauri@unibas.ch
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Hauri
authors.forename: Oliver
authors.initials: O
authors.lastname: Nufer
authors.forename: Lionel
authors.initials: L
authors.lastname: Breuza
authors.forename: Houchaima Ben
authors.initials: HB
authors.lastname: Tekaya
authors.forename: Lu
authors.initials: L
authors.lastname: Liang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D037102:Lectins / Q000737:chemistry / Q000378:metabolism*; D037241:Mannose-Binding Lectins / Q000737:chemistry / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism*; D008969:Molecular Sequence Data; D021381:Protein Transport; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction
chemical_list: D037102:Lectins; D037241:Mannose-Binding Lectins; D008565:Membrane Proteins