Sortilin 1

Sortilin (Sort1) is a protein that in humans is encoded by the SORT1 gene. The SORT1 locus shows the strongest association with serum lipoproteins of any genetic locus in the genome. In hepatocytes, sortilin participates in the presecretory degradation of nascent VLDL particles.

Function

This gene encodes a protein that is a multi-ligand type-1 receptor with similarity to the yeast carboxypeptidase Y sorting receptor Vps10 protein. The encoded protein, a trans-Golgi network (TGN) transmembrane protein, binds a number of unrelated ligands that participate in a wide range of cellular processes; however, it lacks the typical features of a signalling receptor. In the TGN, furin mediates the activation of the mature binding form. The encoded protein consists of a large luminal domain, a single transmembrane segment and short C-terminal cytoplasmic tail. The luminal domain contains a cysteine-rich region similar to two corresponding segments in the yeast Vps10p; the cytoplasmic tail is similar to the corresponding segment of the cation-independent mannose 6-phosphate receptor and the tail also interacts with the VHS domains of GGA (Golgi-associated, gamma-adaptin homologous, ARF-interacting) proteins.

In melanocytic cells SORT1 gene expression may be regulated by MITF.

Interactions

Sortilin 1 has been shown to interact with GGA1 and GGA2.

See also

• Neurotensin receptor