Mannose 6-phosphate

Mannose 6-phosphate
Identifiers
CAS number	3672-15-9 Y
PubChem	65127
ChemSpider	58636 Unspecified anomers Y, 394282 alpha anomer Y, 388338 beta anomer Y
MeSH	mannose-6-phosphate
ChEBI	CHEBI:48066 Y
Jmol-3D images	Image 1
SMILES O=P(O)(O)OC[C@H]1OC(O)[C@@H](O)[C@@H](O)[C@@H]1O
InChI InChI=1S/C6H13O9P/c7-3-2(1-14-16(11,12)13)15-6(10)5(9)4(3)8/h2-10H,1H2,(H2,11,12,13)/t2-,3-,4+,5+,6?/m1/s1 Y Key: NBSCHQHZLSJFNQ-QTVWNMPRSA-N Y
Properties
Molecular formula	C6H13O9P
Molar mass	260.136 g/mol
Y 6-phosphate (verify) (what is: Y/N?) Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Mannose-6-phosphate (M6P) is a molecule bound by lectin in the immune system. M6P is converted to fructose 6-phosphate by mannose phosphate isomerase.

M6P is a targeting signal for acid hydrolase precursor proteins that are destined for transport to lysosomes. The M6P tag is added to such proteins in the cis-Golgi apparatus. Specifically, in a reaction involving uridine diphosphate (UDP) and N-acetylglucosamine, the enzyme UDP-N-acetylglucosamine:N-acetylglucosaminyl-1-phosphotransferase catalyzes the N-linked glycosylation of asparagine residues with M6P. Once appropriately marked with the M6P targeting signal, these proteins are moved to the trans-Golgi. There, the M6P moiety is recognized by mannose 6-phosphate receptor (MPR) proteins.

M6P is also a key marker in ensuring that lysosomal proteins get to the correct organelle within the cell. It attaches to hydrolases. M6P is present on the lysosomal hydrolase at an approximate pH of 6.6 but is released once the pH reaches 6.

The MPRs traffic in vesicles to the lysosome via an endosome.

See also

• insulin-like growth factor 2 receptor
• mannose
• I-cell disease
• Mannose 1-phosphate

External links

• MeSH Mannose-6-Phosphate+Receptor
• Role of M6P in protein modification(video)