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One‐codon alternative splicing of the CpG MTase Dnmt1 transcript in mouse somatic cells
Author(s) -
Lin Meng-Jau,
Lee Tai-Lin,
Hsu Duen-Wei,
Shen C.-K.James
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01254-0
Subject(s) - somatic cell , cpg site , dnmt1 , biology , alternative splicing , methylation , dna methylation , rna splicing , methyltransferase , gene , microbiology and biotechnology , messenger rna , genetics , gene expression , rna
The genomic methylation patterns in the mammalian somatic cells are presumably maintained by a single enzyme, dnmt1. In mouse, this DNA (cytosine‐5)‐methyltransferase, or CpG MTase, is encoded by the Dnmt1 gene. We now present evidence that in different tissues and cell types, the primary transcript of mouse dnmt1 is alternatively spliced to generate two poly‐(A) RNAs of approximately similar abundance. This alternative splicing most likely originates from the existence of two tandemly arranged acceptor sites separated by only 3 nt. The two Dnmt1 mRNAs thus encode two CpG MTases differing by two amino acids. We discuss the implications of the discovery of two dnmt1 isozymes, instead of one enzyme as previously thought, in the somatic cells of both mouse and human.