L3mbtl, the mouse orthologue of the imprinted L3MBTL, displays a complex pattern of alternative splicing and escapes genomic imprinting.
L3mbtl encodes a member of the Polycomb group of proteins, which function as transcriptional repressors in large protein complexes. The Drosophila D-l(3)mbt protein is considered a tumor suppressor since its inactivation results in brain tumors. The human L3MBTL gene lies in a region of chromosome 20 frequently deleted in patients with myeloid malignancies and has been proposed as a candidate 20q tumor suppressor gene. Recently we have shown that L3MBTL undergoes monoallelic methylation in hematopoietic tissues and is transcribed from the paternally derived allele. The mouse L3mbtl gene is located on chromosome 2, a region of syntenic homology with human chromosome 20, and in a region containing a number of genes subject to epigenetic regulation. Here we analyze the genomic structure and alternative splicing of L3mbtl and assess its imprinting status in mouse. L3mbtl displays a complex pattern of alternative splicing involving both 5' noncoding and coding exons and is transcribed from two promoters. Unlike its human counterpart, L3mbtl escapes imprinting and there is no differential methylation of its CpG island.
Li
Juan
J
Department of Haematology, Cambridge Institute for Medical Research, University of Cambridge, Hills Road, Cambridge CB2 2XY, UK.
Bench
Anthony J
AJ
Piltz
Sandie
S
Vassiliou
George
G
Baxter
E Joanna
EJ
Ferguson-Smith
Anne C
AC
Green
Anthony R
AR
D017398:Alternative Splicing / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002868:Chromosomal Proteins, Non-Histone; D018899:CpG Islands; D019175:DNA Methylation; D005091:Exons; D016147:Genes, Tumor Suppressor; D018392:Genomic Imprinting / Q000235:genetics*; D006801:Humans; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic; D012097:Repressor Proteins; D013045:Species Specificity; D025521:Tumor Suppressor Proteins
D002868:Chromosomal Proteins, Non-Histone; C120887:L3MBTL1 protein, human; D009363:Neoplasm Proteins; D012097:Repressor Proteins; D025521:Tumor Suppressor Proteins