Analysis of a naturally occurring mutation in sucrase-isomaltase: glutamine 1098 is not essential for transport to the surface of COS-1 cells.
A glutamine for proline substitution at position 1098 was previously shown to result in accumulation of brush-border sucrase-isomaltase in the Golgi apparatus. The substitution is present in a highly homologous region of the protein, and results in a comparable accumulation when introduced into the same region in lysosomal alpha-glucosidase. To study the importance of the glutamine-1098, we analyzed the transport compatibility of two mutants in which glutamine-1098 is substituted by lysine or alanine. Both mutants were transported to the cell surface and processed comparable to wild type. We concluded that glutamine-1098 is not essential for transport to the cell surface.
Ouwendijk
J
J
Department of Cell Biology and Histology, University of Nijmegen, P.O. Box 9101, 6500 HB Nijmegen, Netherlands.
Peters
W J
WJ
te Morsche
R H
RH
van de Vorstenbosch
R A
RA
Ginsel
L A
LA
Naim
H Y
HY
Fransen
J A
JA
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D001692:Biological Transport / Q000235:genetics; D019556:COS Cells / Q000201:enzymology*; D002462:Cell Membrane / Q000201:enzymology / Q000235:genetics / Q000378:metabolism; D005973:Glutamine / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D011233:Precipitin Tests; D011817:Rabbits; D051381:Rats; D013394:Sucrase-Isomaltase Complex / Q000235:genetics* / Q000378:metabolism*; D014162:Transfection
D008562:Membrane Glycoproteins; D005973:Glutamine; D013394:Sucrase-Isomaltase Complex