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:

• 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.

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