Molecular cloning of a novel splice variant of human type IVA (PDE-IVA) cyclic AMP phosphodiesterase and localization of the gene to the p13.2-q12 region of human chromosome 19 [corrected].
We have isolated from a human T-cell Jurkat cDNA library a novel human cDNA (2EL) that is closely related to the human type-IV PDE splice variant family 'A' (PDE-IVA) cDNA characterized previously by us [Sullivan, Egerton, Shakur, Marquardsen and Houslay (1994) Cell. Signalling 6, 793-812]; (h6.1, PDE-IVA/h6.1; HSPDE4A7). (PDE stands for cyclic nucleotide phosphodiesterase). The novel cDNA 2EL (PDE-IVA/2EL; HSPDE4A8) contains two regions of unique sequence not found in PDE-IVA/h6.1. These are a distinct 5'-end and a 34 bp insert which occurs within a domain thought to encode the type-IV PDE catalytic site and which can be expected to result in premature truncation of any expressed protein. HSPDE4A8 appeared to be catalytically inactive. Isolation and characterization of a human genomic cosmid clone revealed that 2EL and h6.1 represent alternative splice variants of the human PDE-IVA gene. Using a unique sequence found at the 5'-end of the 2EL cDNA, a probe was generated which was used to screen the DNA of human-hamster hybrids. This located the human gene for PDE-IVA to human chromosome 19. Through both the analysis of genomic DNAs from a human-hamster somatic cell hybrid panel and also using fluorescent in situ hybridization, it was shown that the human PDE-IVA gene is located on human chromosome 19, between p13.2 [corrected] and q12. This region on chromosome 19 has been shown to be related to genetic diseases such as the autosomal dominant cerebrovascular disease CADASIL, susceptibility to late-onset Alzheimer's disease and changes seen in benign pituitary and thyroid adenomas.
Horton
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YM
Division of Biochemistry and Molecular Biology, IBLS, University of Glasgow, U.K.
Sullivan
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Houslay
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MD
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000235:genetics*; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D001483:Base Sequence; D002888:Chromosomes, Human, Pair 19; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D005091:Exons; D006801:Humans; D008969:Molecular Sequence Data; D013601:T-Lymphocytes / Q000201:enzymology
D018076:DNA, Complementary; D015105:3',5'-Cyclic-AMP Phosphodiesterases