Peg1/Mest in obese adipose tissue is expressed from the paternal allele in an isoform-specific manner.
Paternally expressed 1 (Peg1)/mesoderm specific transcript (Mest) is an imprinted gene, which is only transcribed from the paternal (father's) allele. In some human cancer tissues, an alternatively spliced variant of PEG1/MEST mRNA using a different promoter of a distinct first exon is expressed from both paternal and maternal alleles. We previously reported that Peg1/Mest expression was markedly up-regulated in obese adipose tissue in mice. Moreover, transgenic overexpression of Peg1/Mest in the adipose tissue resulted in the enlargement of adipocytes in size. Given the potential pathophysiologic relevance in obesity, we examined the nature of increased expression of Peg1/Mest in obese adipose tissue. In obese adipose tissue, expression of Peg1/Mest was increased, but not that of other imprinted genes tested. The transcription rate of Peg1/Mest was increased in obese adipose tissue. We found at least four isoforms of mouse Peg1/Mest generated by use of the alternative first exons. We also demonstrated that the abundantly expressed Peg1/Mest in obese adipose tissue retained monoallelic expression. This is the first report of monoallelic induction of Peg1/Mest in adult tissues.
Kamei
Yasutomi
Y
Department of Molecular Medicine and Metabolism, Medical Research Institute, Tokyo Medical and Dental University, 2-3-10 Kanda-Surugadai, Tokyo, Japan. kamei.mmm@mri.tmd.ac.jp
Suganami
Takayoshi
T
Kohda
Takashi
T
Ishino
Fumitoshi
F
Yasuda
Kazuki
K
Miura
Shinji
S
Ezaki
Osamu
O
Ogawa
Yoshihiro
Y
D017667:Adipocytes / Q000378:metabolism* / Q000473:pathology; D000273:Adipose Tissue / Q000378:metabolism* / Q000473:pathology; D000483:Alleles; D017398:Alternative Splicing; D000818:Animals; D002460:Cell Line; D048429:Cell Size; D005091:Exons; D005786:Gene Expression Regulation; D018392:Genomic Imprinting; D006801:Humans; D051379:Mice; D008820:Mice, Obese; D009369:Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D009765:Obesity / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D019076:Transgenes
D020033:Protein Isoforms; D011506:Proteins; C103637:mesoderm specific transcript protein