Membrane topology of the human seipin protein.
The Berardinelli-Seip congenital lipodystrophy type 2 (BSCL2) gene encodes an integral membrane protein, called seipin, of unknown function localized to the endoplasmic reticulum of eukaryotic cells. Seipin is associated with the heterogeneous genetic disease BSCL2, and mutations in an N-glycosylation motif links the protein to two other disorders, autosomal-dominant distal hereditary motor neuropathy type V and Silver syndrome. Here, we report a topological study of seipin using an in vitro topology mapping assay. Our results suggest that the predominant form of seipin is 462 residues long and has an N(cyt)-C(cyt) orientation with a long luminal loop between the two transmembrane helices.
Department of Biochemistry and Biophysics, Stockholm University, SE-10691 Stockholm, Sweden.
Carolina
C
Lundin
Rickard
R
Nordström
Klaus
K
Wagner
Christian
C
Windpassinger
Helena
H
Andersson
Gunnar
G
von Heijne
IngMarie
I
Nilsson
D020816:Amino Acid Motifs / Q000235:genetics; D025063:Chromosome Disorders / Q000235:genetics / Q000378:metabolism; D003923:Diabetes Mellitus, Lipoatrophic / Q000235:genetics / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000235:genetics / Q000378:metabolism*; D044388:GTP-Binding Protein gamma Subunits / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism*; D046188:Protein Modification, Translational / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics
C432679:BSCL2 protein, human; D044388:GTP-Binding Protein gamma Subunits