acid phosphatase-1 (ACP1, LMW tyrosine phosphatase)

Function

• acts on tyrosine phosphorylated proteins, low-MW aryl phosphates & natural & synthetic acyl phosphates
• isoform 3 does not possess phosphatase activity
• isoform 1 interacts with the SH3 domain of SPTAN1, no interaction observed for isoforms 2 or 3
• inhibited by sulfhydryl reagents

Structure

• belongs to the low molecular weight phosphotyrosine protein phosphatase family

Compartment

cytoplasm

Alternative splicing

• named isoforms=3
• ratio of isoform 1 to isoform 2 is 2:1 in allele A, 4:1 in allele B & 1:4 in allele C

Expression

• erythrocyte acid phosphatase, but not confined to erythrocytes
• T-lymphocytes express only isoform 2

Polymorphism

• ACP1 is genetically polymorphic
• 3 common alleles are known in Caucasians: ACP1*A, ACP1*B & ACP1*C
• they give rise to six different phenotypes
• each allele appears to encode 2 electrophoretically different isozymes, F & S, which are produced in allele-specific ratios

More general terms

• acid phosphatase
• tyrosine phosphatase (protein tyrosine phosphatate, PTP)

Database

• OMIM: https://mirror.omim.org/entry/171500
• UniProt: http://www.uniprot.org/uniprot/P24666.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=52