What is the function of mannose 6-phosphate?

What is the function of mannose 6-phosphate?

Mannose 6 phosphate (M6P) is a sequence tag that plays a pivotal role in transporting proteins from the Golgi complex and cell surface to the lysosome. The M6P sequence is tagged to the N-linked oligosaccharides of lysosomal hydrolases as they traverse the cis-Golgi apparatus.

Can mannose be phosphorylated?

The phosphorylation of lysosomal enzymes on high mannose residues is the first step in the targeting of these enzymes to lysosomes in a wide range of mammalian cells. Phosphorylated lysosomal enzymes bind to mannose 6-phosphate receptors, which divert them from the secretory pathway and direct them toward the lysosome.

Is mannose-6-phosphate a protein?

Mannose-6-phosphate is an N-linked oligosaccharide generated by enzymes present in the cis-Golgi cisterna. It is formed specifically on proteins destined for the lysosome.

What is the mannose-6-phosphate receptor and its significance in vesicle traffic?

Mannose 6-phosphate receptors (MPRs) deliver newly synthesized lysosomal enzymes to endosomes and then recycle to the Golgi. MPR recycling requires Rab9 GTPase; Rab9 recruits the cytosolic adaptor TIP47 and enhances its ability to bind to MPR cytoplasmic domains during transport vesicle formation.

What is the underlying cause of I cell disease?

I-cell disease is caused by a mutation in the GNPTA gene that leads to a deficiency in the enzyme UDP-N-acetylglucoseamine-1-phosphotransferase. I-cell disease is inherited as an autosomal recessive genetic trait.

Is mannose-6-phosphate lysosome?

Introduction. Mannose-6-phosphate (M6P) glycan is a crucial signal for the trafficking of lysosomal enzymes to lysosomes. Most lysosomal enzymes are glycoproteins decorated with high-mannose type glycans as well as complex type glycans.

Where is M6P located?

It is formed specifically on proteins destined for the lysosome. The mannose-6-phosphate receptor spans the Golgi membrane and binds to coat proteins on the cytosolic side of the membrane and to the mannose-6-phosphate-containing protein on the luminal side of the membrane.