Sequences within and adjacent to the transmembrane segment of alpha-2,6-sialyltransferase specify Golgi retention.

AUTOR(ES)

Munro, S

RESUMO

The glycosyltransferase alpha-2,6-sialyltransferase (ST) is a Type II membrane protein localized to the Golgi apparatus. The first 44 amino acids of this protein were able to specify Golgi retention of a fused marker protein, lysozyme. This section of ST contains a transmembrane segment which serves as a non-cleaved signal anchor. When lysozyme was fused to an equivalent region of a cell surface protein it now appeared on the cell surface. Analysis of chimeras between the two proteins revealed that the transmembrane segment of ST specifies Golgi retention. Furthermore, altering this segment in full-length ST results in the protein accumulating on the cell surface. However, the retaining effect of the transmembrane domain of ST is augmented by the presence of adjacent lumenal and cytoplasmic sequences from ST. If these sequences are spaced apart by a transmembrane domain of the same length as that of ST they too can specify Golgi retention. Thus retention in the Golgi of ST appears to involve recognition of an extended region of the protein within and on both sides of the bilayer.

Documentos Relacionados

• An investigation of the role of transmembrane domains in Golgi protein retention.
• Complete cDNA sequence encoding human beta-galactoside alpha-2,6-sialyltransferase.
• Overexpression of the α-2,6-Sialyltransferase in MDCK Cells Increases Influenza Virus Sensitivity to Neuraminidase Inhibitors
• Targeting of a heterodimeric membrane protein complex to the Golgi: rubella virus E2 glycoprotein contains a transmembrane Golgi retention signal.
• Targeting of active sialyltransferase to the plant Golgi apparatus.