TY - JOUR
T1 - Mislocalization of phosphotransferase as a cause of mucolipidosis III αβ
AU - Van Meel, Eline
AU - Qian, Yi
AU - Kornfeld, Stuart A.
PY - 2014/3/4
Y1 - 2014/3/4
N2 - The lysosomal storage disorder mucolipidosis III αβ is caused by mutations in the αβ subunits of UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase (phosphotransferase). This Golgi-localized enzyme mediates the first step in the synthesis of the mannose 6-phosphate recognition marker on lysosomal acid hydrolases, and loss of function results in impaired lysosomal targeting of these acid hydrolases and decreased lysosomal degradation. Here we show that two patient missense mutations, Lys4Gln and Ser15Tyr, in the N-terminal cytoplasmic tail of the α subunit of phosphotransferase impair retention of the catalytically active enzyme in the Golgi complex. This results in mistargeting of the mutant phosphotransferases to lysosomes, where they are degraded, or to the cell surface and release into the medium. The finding that mislocalization of active phosphotransferase is the basis for mucolipidosis III αβ in a subset of patients shows the importance of single residues in the cytoplasmic tail of a Golgi-resident protein for localization to this compartment.
AB - The lysosomal storage disorder mucolipidosis III αβ is caused by mutations in the αβ subunits of UDP-GlcNAc:lysosomal enzyme N-acetylglucosamine-1-phosphotransferase (phosphotransferase). This Golgi-localized enzyme mediates the first step in the synthesis of the mannose 6-phosphate recognition marker on lysosomal acid hydrolases, and loss of function results in impaired lysosomal targeting of these acid hydrolases and decreased lysosomal degradation. Here we show that two patient missense mutations, Lys4Gln and Ser15Tyr, in the N-terminal cytoplasmic tail of the α subunit of phosphotransferase impair retention of the catalytically active enzyme in the Golgi complex. This results in mistargeting of the mutant phosphotransferases to lysosomes, where they are degraded, or to the cell surface and release into the medium. The finding that mislocalization of active phosphotransferase is the basis for mucolipidosis III αβ in a subset of patients shows the importance of single residues in the cytoplasmic tail of a Golgi-resident protein for localization to this compartment.
UR - http://www.scopus.com/inward/record.url?scp=84895801212&partnerID=8YFLogxK
U2 - 10.1073/pnas.1401417111
DO - 10.1073/pnas.1401417111
M3 - Article
C2 - 24550498
AN - SCOPUS:84895801212
SN - 0027-8424
VL - 111
SP - 3532
EP - 3537
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 9
ER -