Phosphatase Family HP1
Phosphatase Classification: Fold HP: Superfamily HP (histidine phosphatase): HP, branch1 family
Subfamilies found in human
PGAM
PGAMs mainly function as glycolytic enzymes regulating intracellular levels of their substrate 3-phosphoglycerate and product 2-phosphoglycerate. Human BPGM is a 2,3-bisphosphoglycerate mutase. They are found throughout most eukaryotes.
PGAM5
PGAM5 is a protein phosphatase conserved in metazoa. It has distinct substrates, such as ASK1, Drp1, FUNDC1.
TIGAR: TP53 Induced Glycolysis and Apoptosis Regulatory phosphatase
TIGAR inhibits glycolysis and negatively modulates the level of intracellular reactive oxygen species (ROS), therefore regulating autophagy and apoptosis. TIGAR is found in chordates some basal eumetazoan, but is absent from nematodes and arthropoda.
STS (TULA or UBASH3)
STS is a protein tyrosine phosphatase involved in T-cell receptor signaling. In particular, STS dephosphorylates kinases Syk and ZAP-70 of Syk subfamily. STS is conserved in metazoa, but C. elegans lost the signature domains, SH3 and H2 domain, which are common among STSs.
PFKFB
PFKFB is a bifunctional enzyme responsible for the synthesis (as kinase) and degradation (as phosphatase) of fructose-2,6-bisphosphate a metabolite that controls glycolysis. Its two opposite enzymatic activities are encoded in two separate domains, N-terminal kinase domain and C-terminal phosphatase domain. PFKFB is found in most eukaryotes, often multiple copies per genome (human has four copies with different tissue expression). It emerged by gene fusion of the ancestors of the gene containing kinase domain and that containing phosphatase domain.
Other subfamilies
TFC7
TFC7 is a RNA pol III transcription initiation factor complex (TFIIIC) subunit found in fungi and Dictyostelium.
HP1LE
HP1LE subfamily is found in choanoflagellates and sponge, but is absent from eumetazoan. Its function is unclear.