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PiUS (Pi uptake stimulator) is an inositol hexakisphosphate kinase
Author(s) -
Schell Michael J.,
Letcher Andrew J.,
Brearley Charles A.,
Biber Jürg,
Murer Heini,
Irvine Robin F.
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)01462-3
Subject(s) - inositol , inositol phosphate , xenopus , kinase , biochemistry , pi , inositol trisphosphate , sugar phosphates , biology , phosphate , chemistry , inositol trisphosphate receptor , microbiology and biotechnology , receptor , gene
A cDNA cloned from its ability to stimulate inorganic phosphate uptake in Xenopus oocytes (phosphate uptake stimulator (PiUS)) shows significant similarity with inositol 1,4,5‐trisphosphate 3‐kinase. However, the expressed PiUS protein showed no detectable activity against inositol 1,4,5‐trisphosphate, nor the 1,3,4,5‐ or 3,4,5,6‐isomers of inositol tetrakisphosphate, whereas it was very active in converting inositol hexakisphosphate (InsP 6 ) to inositol heptakisphosphate (InsP 7 ). PiUS is a member of a family of enzymes found in many eukaryotes and we discuss the implications of this for the functions of InsP 7 and for the evolution of inositol phosphate kinases.