Phylogeny and function of the invertebrate p53 superfamily

Abstract

The origin of the p53 superfamily predates animal evolution and first appears in unicellular Flagellates. Invertebrate p53 superfamily members appear to have a p63-like domain structure, which seems to be evolutionarily ancient. The radiation into p53, p63, and p73 proteins is a vertebrate invention. In invertebrate models amenable to genetic analysis p53 superfamily members mainly act in apoptosis regulation in response to genotoxic agents and do not have overt developmental functions. We summarize the literature on cnidarian and mollusc p53 superfamily members and focus on the function and regulation of Drosophila melanogaster and Caenorhabditis elegans p53 superfamily members in triggering apoptosis. Furthermore, we examine the emerging evidence showing that invertebrate p53 superfamily proteins also have functions unrelated to apoptosis, such as DNA repair, cell cycle checkpoint responses, compensatory proliferation, aging, autophagy, and innate immunity.

Figure 1.

Phylogenetic tree of the p53 superfamily. Sequences corresponding to the conserved DNA binding domain (Supplementary File 1) was used to generate an Unrooted Phylogenetic Tree using the Splits Tree 4 program (Huson and Bryant 2006). Full sequences and annotations can be found in Supplementary File 2. Abbreviations used are: Ag, Anopheles gambiae; Ap, Apisum; Bf, Branchiostoma floridae, (Amphioxus); Cbr, Caenorhabditis brenneri; Cbri, Caenorhabditis briggsae; Ce, Caenorhabditis elegans; Ci, Ciona intestinalis; Co, Capsaspora owczarzaki, Cp, Capitella sp; Cq, Culex quinquefasciatus; Cre, Caenorhabditis remanei; Cs, Ciona savignyi; Dp, Daphina pulex; Dm, Drosophila melanogaster; Dr, Danio rerio (Zebrafish); Hr, Helobdella robusta; Hs, Homo sapiens; Lf, Loligo forbesi; Lg Lottia gigantea; Ma, Mya arenaria; Mb, Monosiga brevicollis; Me Mytilus edulis; Nav, Nasonia vitripennes; Nv, Nematostella vectensis; Ph, Pediculus humanus; Pp Pristionchus pacificus; shark (Elephant shark); Little skate (Leucoraja erinacea); Strongylocentrotus purpuratus; Ta, Trichoplax sp; Tc, Tribolium castaneum; Tp, Trichonella sp.