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.
Interdisciplinary Research Institute (IRIBHN), Université Libre de Bruxelles, Belgium.
F
F
De Smedt
B
B
Verjans
P
P
Mailleux
C
C
Erneux
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