Phosphatase Fold PHP

Phosphatase Classification: PHP Fold

PHP is the only phosphatase known to be histidine-specific.

Evolution

PHP is found throughout eukaryotes, though lost from fungi. It is usually single copy per genome, but four are found in fruit fly.

Domain

PHP has a single domain: catalytic domain. The structure of the domain has been solved and a potential enzymatic mechanism proposed [1].

Functions

Several substrates have been reported, including beta subunit of heterotrimeric G proteins [2], the metabolic enzyme adenosine 5’-triphosphate-citrate lyase (ACL) [3], and the Ca2+-activated K+ channel KCa3.1 [4]. These are known or suspected substrates of the nucleoside diphosphate kinases (NDK).

Its role in neuronal cells is particularly interesting. In C. elegans, the ortholog is expressed exclusively in neurons [5]. In human cells, the overexpression of PHPT1 decreases the activity of adenosine 5’-triphosphate-citrate lyase (ACL) and reduces the viability of neuronal cells [6].

References

Error fetching PMID 18991813:
Error fetching PMID 16039992:
Error fetching PMID 12788074:
Error fetching PMID 18796614:
Error fetching PMID 12468887:
Error fetching PMID 19138678: