ARSG
Function
Displays arylsulfatase activity at acidic pH towards artificial substrates, such as p-nitrocatechol sulfate and also, but with a lower activity towards p-nitrophenyl sulfate and 4-methylumbelliferyl sulfate (PubMed:18283100, PubMed:29300381). Catalyzes the hydrolysis of the 3-sulfate groups of the N-sulfo-D-glucosamine 3-O-sulfate units of heparin (PubMed:22689975).
Involvement in disease
Usher syndrome 4
USH4
A form of Usher syndrome, a genetically heterogeneous condition characterized by the association of retinitis pigmentosa with sensorineural deafness. Age at onset and differences in auditory and vestibular function distinguish different types of Usher syndrome. USH4 is characterized by late onset of retinitis pigmentosa and usually late-onset of progressive sensorineural hearing loss without vestibular involvement. USH4 inheritance is autosomal recessive.
None
The disease is caused by variants affecting the gene represented in this entry.
Post-translational modifications
N-glycosylated (PubMed:18283100). N-glycosylated with both high mannose and complex type sugars (By similarity).
The conversion to 3-oxoalanine (also known as C-formylglycine, FGly), of a serine or cysteine residue in prokaryotes and of a cysteine residue in eukaryotes, is critical for catalytic activity.
The 63-kDa precursor undergoes proteolytic processing in two steps, yielding two fragments in the first step (apparent molecular masses of 44 and 18 kDa) (PubMed:25135642). In the second step, the 44-kDa fragment is processed further to the 34- and 10-kDa chains. The 10-kDa chain is a cleavage product of the 44-kDa fragment but linked to the 18-kDa chain through a disulfide bridge (PubMed:25135642).
Sequence Similarities
Belongs to the sulfatase family.
Tissue Specificity
Widely expressed, with very low expression in brain, lung, heart and skeletal muscle.
Cellular localization
- Lysosome
- The 63-kDa precursor protein localizes to pre-lysosomal compartments and tightly associates with organelle membranes, most likely the endoplasmic reticulum. In contrast, proteolytically processed fragments of 34-, 18- and 10-kDa are found in lysosomal fractions and lose their membrane association.
Alternative names
KIAA1001, UNQ839/PRO1777, ARSG, Arylsulfatase G, ASG, N-sulfoglucosamine-3-sulfatase