The cDNA of a human lymphocyte cyclic-AMP phosphodiesterase (PDE IV) reveals a multigene family.
Five protein families are needed to encompass the diversity of cyclic-AMP (cAMP) phosphodiesterases (PDE). Family IV PDEs (PDE IV) specifically hydrolyze cAMP with a low Km, and are selectively inhibited by rolipram (Rp) and related drugs. Cloned cDNAs from rat (r) suggest that the PDE IV family comprises four distinct members, designated A, B, C and D. Using RN from a human lymphocytic B-cell line (43D-Cl2), we have isolated a 3.8-kb cDNA by low-stringency screening using a rat PDE IV member B (r-PDE IVB) probe. Expression of the human (h) cDNA in Escherichia coli results in cAMP-specific PDE activity that is Rp sensitive. A single large open reading frame (ORF) predicts a 564-amino-acid protein with 92.9% identity to r-PDE IVB; at the nucleotide level the identity is 86.3%. This h-PDE IVB clone, HPB106, differs from a related cDNA clone isolated by others from h-monocytes [Livi et al., Mol. Cell. Biol. 10 (1990) 2678-2686]. Our analysis identifies the monocyte clone with r-PDE IVA. Southern blots using a 1.2-kb h-PDE IVB probe at low stringency suggest the presence of additional uncloned human PDE IV family members. Analysis of genomic Southern blots using short specific probes from the h-PDE IVA and h-PDE IVB cDNAs indicates that distinct genes encode these two PDE IV family members. RNA from fractionated normal human leukocytes shows major specific messages of 3.0 and 4.6 kb for h-PDE IVA and 3.7 kb for h-PDE IVB.(ABSTRACT TRUNCATED AT 250 WORDS)
Syntex Discovery Research, Institute of Bio-Organic Chemistry, Palo Alto, CA 94304.
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Obernolte
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Bhakta
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Alvarez
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Bach
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Zuppan
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Mulkins
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Jarnagin
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Shelton
D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics*; D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001402:B-Lymphocytes; D001483:Base Sequence; D001665:Binding Sites; D015152:Blotting, Northern; D015139:Blotting, Southern; D002460:Cell Line; D004274:DNA, Recombinant; D004926:Escherichia coli; D014644:Genetic Variation; D006801:Humans; D007527:Isoenzymes; D008969:Molecular Sequence Data; D005810:Multigene Family; D016133:Polymerase Chain Reaction; D011499:Protein Processing, Post-Translational; D011760:Pyrrolidinones / Q000494:pharmacology; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics; D020889:Rolipram; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D004274:DNA, Recombinant; D007527:Isoenzymes; D011760:Pyrrolidinones; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D020889:Rolipram