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, GNPTG produces the gamma subunit. 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. Surprisingly some lyosomal enzyme are only tagged at a rate of 5% or lower.
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
- stuttering (Kang et al., 2010)
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.
Kang, C., Riazuddin, S., Mundorff, J., Krasnewich, D., Friedman, P., Mullikin, J.C., and Drayna, D. (2010). Mutations in the Lysosomal Enzyme–Targeting Pathway and Persistent Stuttering. New England Journal of Medicine 362, 677-685.
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
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