title: Proteolytic cleavage of LEDA-1/PIANP by furin-like proprotein convertases precedes its plasma membrane localization.
abstract: Liver endothelial differentiation-associated protein-1 (LEDA-1/PIANP) is a type-I-transmembrane protein first identified by us as a putative junctional protein in liver sinusoidal endothelial cells. Others have shown that LEDA-1/PIANP binds and activates immune inhibitory receptor PILRα in trans, a process that requires sialidation of LEDA-1/PIANP. Here we show that LEDA-1/PIANP is subject to O-glycosylation and sialidation as demonstrated in brain tissue as well as in LEDA-1 expressing cell lines by using anti-LEDA-1/PIANP C-terminal antibodies. In addition, analysis of LEDA-1/PIANP processing with His-tags inserted at different positions in the extracellular domain revealed that multiple steps of proteolytic cleavage occur during maturation of the protein. Proteolytic cleavage between aa59 and aa83 preceded sorting of the protein to the plasma membrane. Deletion of aa75-79 and inhibition with Furin inhibitor I confirmed that LEDA-1/PIANP is processed by a Furin-like proprotein convertase. In summary, these findings show that Furin-like proprotein convertase-dependent processing precedes plasma membrane localization of LEDA-1/PIANP that is a pre-requisite of functional receptor-ligand interactions in vitro and in vivo.
authors.affiliation: Department of Dermatology, Venereology and Allergology, University Medical Center and Medical Faculty Mannheim, Heidelberg University and Center of Excellence in Dermatology, Mannheim, Germany.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Evdokimov
authors.forename: Siladitta
authors.initials: S
authors.lastname: Biswas
authors.forename: Monica
authors.initials: M
authors.lastname: Adrian
authors.forename: Jochen
authors.initials: J
authors.lastname: Weber
authors.forename: Kai
authors.initials: K
authors.lastname: Schledzewski
authors.forename: Manuel
authors.initials: M
authors.lastname: Winkler
authors.forename: Sergij
authors.initials: S
authors.lastname: Goerdt
authors.forename: Cyrill
authors.initials: C
authors.lastname: Géraud
mesh_terms: D000818:Animals; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D003412:Cricetulus; D004285:Dogs; D004730:Endothelium, Vascular / Q000166:cytology / Q000201:enzymology / Q000378:metabolism; D045683:Furin / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D008024:Ligands; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D009419:Nerve Tissue Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D043484:Proprotein Convertases / Q000378:metabolism*; D025941:Protein Interaction Mapping; D011499:Protein Processing, Post-Translational; D059748:Proteolysis
chemical_list: D008024:Ligands; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; C557210:PIANP protein, human; C557209:Pianp protein, mouse; D043484:Proprotein Convertases; D045683:Furin