Cloning and expression of human brain type I inositol 1,4,5-trisphosphate 5-phosphatase. High levels of mRNA in cerebellar Purkinje cells.
In brain and many other tissues, Type I inositol 1,4,5-trisphosphate (InsP3) 5-phosphatase is the major isozyme hydrolysing the calcium-mobilizing second messenger InsP3. We recently reported the cloning and expression of dog thyroid InsP3 5-phosphatase. During the course of this cloning, screening of a human brain cDNA library allowed us to isolate a cDNA clone D1 with 91% sequence identity with the thyroid sequence. When clone D1 was expressed in Escherichia coli, the fusion protein had InsP3 5-phosphatase activity. M(r) estimates of the recombinant enzyme made by immunodetection, activity assay after SDS/PAGE or silver staining were consistent with the calculated molecular mass. In situ hybridization on human cerebellum sections localised the mRNA for this enzyme to the Purkinje cells.
De Smedt
F
F
Interdisciplinary Research Institute (IRIBHN), Université Libre de Bruxelles, Belgium.
Verjans
B
B
Mailleux
P
P
Erneux
C
C
D000595:Amino Acid Sequence; D001483:Base Sequence; D002531:Cerebellum / Q000033:anatomy & histology / Q000201:enzymology*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D006801:Humans; D017403:In Situ Hybridization; D000072181:Inositol Polyphosphate 5-Phosphatases; D007527:Isoenzymes / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D010744:Phosphoric Monoester Hydrolases / Q000096:biosynthesis / Q000235:genetics* / Q000302:isolation & purification; D011689:Purkinje Cells / Q000201:enzymology*; D011994:Recombinant Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D014018:Tissue Distribution
D018076:DNA, Complementary; D007527:Isoenzymes; D011994:Recombinant Proteins; D010744:Phosphoric Monoester Hydrolases; D000072181:Inositol Polyphosphate 5-Phosphatases