Recognition of arylsulfatase A and B by the UDP-N-acetylglucosamine:lysosomal enzyme N-acetylglucosamine-phosphotransferase.
The critical step for sorting of lysosomal enzymes is the recognition by a Golgi-located phosphotransferase. The topogenic structure common to all lysosomal enzymes essential for this recognition is still not well defined, except that lysine residues seem to play a critical role. Here we have substituted surface-located lysine residues of lysosomal arylsulfatases A and B. In lysosomal arylsulfatase A only substitution of lysine residue 457 caused a reduction of phosphorylation to 33% and increased secretion of the mutant enzyme. In contrast to critical lysines in various other lysosomal enzymes, lysine 457 is not located in an unstructured loop region but in a helix. It is not strictly conserved among six homologous lysosomal sulfatases. Based on three-dimensional structure comparison, lysines 497 and 507 in arylsulfatase B are in a similar position as lysine 457 of arylsulfatase A. Also, the position of oligosaccharide side chains phosphorylated in arylsulfatase A is similar in arylsulfatase B. Despite the high degree of structural homology between these two sulfatases substitution of lysines 497 and 507 in arylsulfatase B has no effect on the sorting and phosphorylation of this sulfatase. Thus, highly homologous lysosomal arylsulfatases A and B did not develop a single conserved phosphotransferase recognition signal, demonstrating the high variability of this signal even in evolutionary closely related enzymes.
Yaghootfam
Afshin
A
Institute of Physiological Chemistry, Rheinische-Friedrich-Wilhelms Universität, Nussallee 11, 53115 Bonn, Germany.
Schestag
Frank
F
Dierks
Thomas
T
Gieselmann
Volkmar
V
D000818:Animals; D002460:Cell Line; D002553:Cerebroside-Sulfatase / Q000737:chemistry*; D006224:Cricetinae; D018076:DNA, Complementary / Q000378:metabolism; D006031:Glycosylation; D008239:Lysine / Q000737:chemistry; D008247:Lysosomes / Q000201:enzymology; D008958:Models, Molecular; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D020051:N-Acetylgalactosamine-4-Sulfatase / Q000737:chemistry*; D009844:Oligosaccharides / Q000737:chemistry; D010766:Phosphorylation; D011233:Precipitin Tests; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D014162:Transfection; D017855:Transferases (Other Substituted Phosphate Groups) / Q000737:chemistry* / Q000378:metabolism*; D014537:Uridine Diphosphate N-Acetylglucosamine / Q000737:chemistry
D018076:DNA, Complementary; D009844:Oligosaccharides; D014537:Uridine Diphosphate N-Acetylglucosamine; D017855:Transferases (Other Substituted Phosphate Groups); C030012:UDP-N-acetylglucosamine-lysosomal-enzyme-N-acetylglucosaminephosphotransferase; D020051:N-Acetylgalactosamine-4-Sulfatase; D002553:Cerebroside-Sulfatase; D008239:Lysine