A wide-range phylogenetic analysis of Zic proteins: implications for correlations between protein structure conservation and body plan complexity.
We compared Zic homologues from a wide range of animals. Striking conservation was found in the zinc finger domains, in which an exon-intron boundary has been kept in all bilateralians but not cnidarians, suggesting that all of the bilateralian Zic genes are derived from a single gene in a bilateralian ancestor. There were additional conserved amino acid sequences, ZOC and ZF-NC. Combined analysis of the zinc finger, ZOC, and ZF-NC revealed the presence of two classes of Zic, based on the degree of protein structure conservation. The "conserved" class includes Zic proteins from the Arthropoda, Mollusca, Annelida, Echinodermata, and Chordata (vertebrates and cephalochordates), whereas the "diverged" class contains those from the Platyhelminthes, Cnidaria, Nematoda, and Chordata (urochordates). The result indicates that the ancestral bilateralian Zic protein had already acquired an entire set of conserved domains, but that this was lost and diverged in the platyhelminthes, nematodes, and urochordates.
Laboratory for Comparative Neurogenesis, RIKEN Brain Science Institute, Wako 351-0198, Japan. jaruga@brain.riken.jp
Jun
J
Aruga
Akiko
A
Kamiya
Hirokazu
H
Takahashi
Takahiko J
TJ
Fujimi
Yuri
Y
Shimizu
Keiko
K
Ohkawa
Shigenobu
S
Yazawa
Yoshihiko
Y
Umesono
Hideki
H
Noguchi
Takashi
T
Shimizu
Naruya
N
Saitou
Katsuhiko
K
Mikoshiba
Yoshiyuki
Y
Sakaki
Kiyokazu
K
Agata
Atsushi
A
Toyoda
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019521:Body Patterning / Q000235:genetics*; D017124:Conserved Sequence; D018076:DNA, Complementary / Q000235:genetics; D019143:Evolution, Molecular; D005091:Exons; D006801:Humans; D007438:Introns; D008957:Models, Genetic; D008969:Molecular Sequence Data; D015394:Molecular Structure; D005810:Multigene Family; D010802:Phylogeny; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D014157:Transcription Factors / Q000737:chemistry* / Q000235:genetics*; D016335:Zinc Fingers / Q000235:genetics*
D018076:DNA, Complementary; D014157:Transcription Factors