N-acetylglucosamine-1-phosphate transferase

N-acetylglucosamine-1-phosphate transferase, alpha and beta subunits
Identifiers
Symbol	GNPTAB
Alt. symbols	GNPTA
Entrez	79158
HUGO	29670
OMIM	607840
RefSeq	NM_024312
UniProt	Q3T906
Other data
Locus	Chr. 12 q23.3

N-acetylglucosamine-1-phosphate transferase, gamma subunit
Identifiers
Symbol	GNPTG
Alt. symbols	GNPTAG
Entrez	84572
HUGO	23026
OMIM	607838
RefSeq	NM_032520
UniProt	Q9UJJ9
Other data
Locus	Chr. 16 p13.3

N-acetylglucosamine-1-phosphate transferase is a transferase enzyme.

Function

It is made up of two alpha (α), two beta (β), and two gamma (γ) subunits. GNPTAB produces the alpha and beta subunits. GlcNAc-1-phosphotransferase functions to prepare newly made enzymes for lysosome transportation (lysosomal hydrolases to the lysosome). Lysosomes, a part of an animal cells, helps break down large molecules into smaller ones that can be reused. GlcNAc-1-phosphotransferase catalyzes the N-linked glycosylation of asparagine residues with a molecule called mannose-6-phosphate (M6P). M6P acts as indicator whether a hydrolase should be transported to the lysosome or not. Once a hydrolase has the indication from an M6P, it can be transported to a lysosome.

Clinical significance

It is associated with the following conditions:^[1]^[2]

mucolipidosis II alpha/beta (I-cell disease) - GNPTAB
mucolipidosis III alpha/beta (pseudo-Hurler polydystrophy) - GNPTAB
mucolipidosis III gamma - GNPTG

In melanocytic cells GNPTG gene expression may be regulated by MITF.^[3]

References

↑ Online 'Mendelian Inheritance in Man' (OMIM) MUCOLIPIDOSIS II ALPHA/BETA -252500
↑ Online 'Mendelian Inheritance in Man' (OMIM) MUCOLIPIDOSIS III GAMMA -252605
↑ Hoek KS, Schlegel NC, Eichhoff OM, et al. (2008). "Novel MITF targets identified using a two-step DNA microarray strategy". Pigment Cell Melanoma Res. 21 (6): 665–76. doi:10.1111/j.1755-148X.2008.00505.x. PMID 19067971.

External links

GeneReviews/NCBI/NIH/UW entry on Mucolipidosis III Alpha/Beta
GeneReviews/NIH/NCBI/UW entry on Mucolipidosis II
GeneReviews/NIH/NCBI/UW entry on Mucolipidosis III Gamma
N-acetylglucosamine-1-phosphate transferase at the US National Library of Medicine Medical Subject Headings (MeSH)
EC 2.7.8.15

Transferases: phosphorus-containing groups (EC 2.7)

2.7.1-2.7.4:
phosphotransferase/kinase
(PO₄)

2.7.1: OH acceptor	Hexo- Gluco- Fructo- Hepatic Galacto- Phosphofructo- 1 Liver Muscle Platelet 2 Riboflavin Shikimate Thymidine ADP-thymidine NAD⁺ Glycerol Pantothenate Mevalonate Pyruvate Deoxycytidine PFP Diacylglycerol Phosphoinositide 3 Class I PI 3 Class II PI 3 Sphingosine Glucose-1,6-bisphosphate synthase

2.7.2: COOH acceptor	Phosphoglycerate Aspartate kinase

2.7.3: N acceptor	Creatine

2.7.4: PO₄ acceptor	Phosphomevalonate Adenylate Nucleoside-diphosphate Uridylate Guanylate Thiamine-diphosphate

2.7.6: diphosphotransferase
(P₂O₇)

2.7.7: nucleotidyltransferase
(PO₄-nucleoside)

Polymerase

DNA polymerase	DNA-directed DNA polymerase I II III IV V RNA-directed DNA polymerase Reverse transcriptase Telomerase DNA nucleotidylexotransferase/Terminal deoxynucleotidyl transferase

RNA nucleotidyltransferase	RNA polymerase/DNA-directed RNA polymerase RNA polymerase I RNA polymerase II RNA polymerase III RNA polymerase IV Primase RNA-dependent RNA polymerase PNPase

Phosphorolytic
3' to 5' exoribonuclease

Nucleotidyltransferase

Guanylyltransferase

mRNA capping enzyme

Other

2.7.8: miscellaneous

Phosphatidyltransferases	CDP-diacylglycerol—glycerol-3-phosphate 3-phosphatidyltransferase CDP-diacylglycerol—serine O-phosphatidyltransferase CDP-diacylglycerol—inositol 3-phosphatidyltransferase CDP-diacylglycerol—choline O-phosphatidyltransferase

Glycosyl-1-phosphotransferase	N-acetylglucosamine-1-phosphate transferase

2.7.10-2.7.13: protein kinase
(PO₄; protein acceptor)

2.7.10: protein-tyrosine	see tyrosine kinases

2.7.11: protein-serine/threonine	see serine/threonine-specific protein kinases

2.7.12: protein-dual-specificity	see serine/threonine-specific protein kinases

2.7.13: protein-histidine	Protein-histidine pros-kinase Protein-histidine tele-kinase Histidine kinase

Metabolism: carbohydrate metabolism · glycoprotein enzymes

Anabolism	Dolichol kinase GCS1 Oligosaccharyltransferase

Catabolism	Neuraminidase Beta-galactosidase Hexosaminidase mannosidase alpha-Mannosidase beta-mannosidase Aspartylglucosaminidase Fucosidase NAGA

Transport	SLC17A5

M6P tagging	N-acetylglucosamine-1-phosphate transferase

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