Murine UDP-GlcNAc:Lysosomal Enzyme N-Acetylglucosamine-1-phosphotransferase Lacking the γ-Subunit Retains Substantial Activity toward Acid Hydrolases

UDP-GlcNAc:lysosomal enzyme N -acetylglucosamine-1-phosphotransferase (GlcNAc-1-phosphotransferase) mediates the first step in the synthesis of the mannose 6-phosphate recognition marker on acid hydrolases. The transferase exists as anα 2 β 2 γ 2 hexameric complex with the α- and β-subunits der...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:The Journal of biological chemistry 2007-09, Vol.282 (37), p.27198
Hauptverfasser: Wang-Sik Lee, Bobby Joe Payne, Claire M. Gelfman, Peter Vogel, Stuart Kornfeld
Format: Artikel
Sprache:eng
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:UDP-GlcNAc:lysosomal enzyme N -acetylglucosamine-1-phosphotransferase (GlcNAc-1-phosphotransferase) mediates the first step in the synthesis of the mannose 6-phosphate recognition marker on acid hydrolases. The transferase exists as anα 2 β 2 γ 2 hexameric complex with the α- and β-subunits derived from a single precursor molecule. The catalytic function of the transferase is attributed to the α- and β-subunits, whereas the γ-subunit is believed to be involved in the recognition of a conformation-dependent protein determinant common to acid hydrolases. Using knock-out mice with mutations in either the α/β gene or the γ gene, we show that disruption of the α/β gene completely abolishes phosphorylation of high mannose oligosaccharides on acid hydrolases whereas knock-out of the γ gene results in only a partial loss of phosphorylation. These findings demonstrate that the α/β-subunits, in addition to their catalytic function, have some ability to recognize acid hydrolases as specific substrates. This process is enhanced by the γ-subunit.
ISSN:0021-9258
1083-351X
DOI:10.1074/jbc.M704067200