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Isolation of cDNA clones encoding human acid sphingomyelinase: occurrence of alternatively processed transcripts. EMBO J 1989 Sep;8(9):2469-73

Date

09/01/1989

Pubmed ID

2555181

Pubmed Central ID

PMC401234

Scopus ID

2-s2.0-0024423426   128 Citations

Abstract

Acid sphingomyelinase (sphingomyelin phosphodiesterase, EC 3.1.4.12) was purified from human urine and 12 tryptic peptides were microsequenced (128 residues). Based on regions of minimal codon redundancy, four oligonucleotide mixtures were synthesized and oligonucleotide mixture 1 (20mer; 256 mix) was used to screen 3 X 10(6) independent recombinants from a human fibroblast cDNA library. Putative positive clones (92) were purified and analyzed by Southern hybridization with oligonucleotide mixtures 2-4. These studies revealed two groups of clones; group 1 (80 clones; inserts ranging from approximately 1.2 to 1.6 kb) hybridized with oligonucleotides mixtures 1-4, while group II (12 clones; inserts ranging from approximately 1.2 to 1.4 kb) hybridized with oligonucleotide mixtures 1-3. Several group II clones had larger inserts than those in group I, but did not hybridize with oligonucleotide mixture 4. Screening of a human placental cDNA library with a 450 bp group I fragment, also resulted in the isolation of group I and II clones. Representative clones from group I (pASM-1) and group II (pASM-2) were sequenced. pASM-1 contained a 1879 bp insert which was colinear with 96 microsequenced amino acids, while the pASM-2 1382 bp insert was colinear with 78 microsequenced residues. Notably, pASM-2 did not have an internal 172 bp sequence encoding 57 amino acid residues, but had instead an in-frame 40 bp sequence encoding 13 amino acids which was not present in pASM-1. These findings demonstrate the presence of two distinct acid sphingomyelinase transcripts in human fibroblasts and placenta and suggest the occurrence of alternative processing of the mRNA encoding this lysosomal hydrolase.

Author List

Quintern LE, Schuchman EH, Levran O, Suchi M, Ferlinz K, Reinke H, Sandhoff K, Desnick RJ

Author

Mariko Suchi MD, PhD Associate Professor in the Pathology department at Medical College of Wisconsin




MESH terms used to index this publication - Major topics in bold

Amino Acid Sequence
Base Sequence
Blotting, Southern
Cloning, Molecular
Humans
Introns
Molecular Sequence Data
Oligonucleotide Probes
Phosphoric Diester Hydrolases
RNA Splicing
Sphingomyelin Phosphodiesterase
jenkins-FCD Prod-482 91ad8a360b6da540234915ea01ff80e38bfdb40a