The Fatty Acid Synthase Gene is a Conserved p53 Family Target Gene from Worm to Human
Volume 5, Issue 7
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April 1, 2006
Pages 750 - 758http://dx.doi.org/10.4161/cc.5.7.2622
Authors: Anna Maria D’Erchia, Apollonia Tullo, Konstantinos Lefkimmiatis, Cecilia Saccone and Elisabetta Sbisà View affiliations
The discovery that the p53 family consists of three members (p53, p63 and p73) in vertebrates and of a single homolog in invertebrates has raised the challenge of understanding the functions of the ancestor and how they have evolved and differentiated within the duplicated genes in vertebrates. Here, we report that the fatty acid synthase (FAS) gene, encoding for a key enzyme involved in the biogenesis of membrane lipids in rapidly proliferating cells, is a conserved target of the p53 family
throughout the evolution. We show that CEP-1, the C. elegans p53 homolog, is able to bind the two p53 family responsive elements (REs) identified in the worm fasn-1 gene. Moreover, we demonstrate that fasn-1 expression is modulated by CEP-1 in vivo, by comparing wild-type and CEP-1 knockout worms. In human, luciferase and chromatin immunoprecipitation assays demonstrate that TAp73? and &DELTA;Np63?, but not p53, TAp73? and TAp63? bind the two p53 REs of the human FASN gene. We show that the ectopic expression of TAp73? and &DELTA;Np63? leads to an increase of FASN mRNA levels, while their silencing produces a decrease of FASN expression.
Furthermore, we present data showing a correlation between ?Np63? and FASN expression in
Of relevant importance is that fasn-1 is the first CEP-1 direct target gene identified so far in C.
elegans and our results suggest a new CEP-1 role in cellular proliferation and development, besides
the one already described in apoptosis of germ cells. These data confirm the hypothesis that the
ancestral functions of the single invertebrate gene may have been spread out among the three
vertebrate members, each of them have acquired specific role in cell cycle regulation.