Structure determination and evolution of the chicken cDNA and gene encoding prepropancreatic polypeptide.
We have previously demonstrated that the C-terminal regions of the rat and human pancreatic polypeptide (PPP) precursors exhibit a high degree of divergence, whereas the N-terminal regions are highly conserved. This blend of structural conservation and divergence in the precursors appears to be caused by splice junction sliding and translational frameshift in the 3'-region of the PPP gene [Yonekura et al., J. Biol. Chem. 263 (1988) 2990-2997]. In the present study, we determined the nucleotide (nt) sequences of the chicken PPP (cPPP) cDNA and gene, and compared them with those of the mammals. In cPPP, the C-terminal region of the precursor is quite heterologous with respect to the rat (rPPP) and human (hPPP) precursors, and this heterogeneity is accentuated by the large deletion in exon 3 of cPPP. Furthermore, mutational accumulation during evolution caused the structural organization of the 3'-region of cPPP to change; cPPP is terminated in exon 3, whereas rPPP and hPPP are terminated in exon 4. Thus, our previous observation regarding the possibility of 'mosaic evolution' [Yamamoto et al., J. Biol. Chem. 261 (1986) 6156-6159] of PPP has been extended and confirmed by this study. Available evidence suggests that 'mosaic evolution' is a phenomenon unique to PPP, and not to the genes encoding the other members of the PPP family, neuropeptide-Y and peptide-YY.
Nata
K
K
Department of Biochemistry, Tohoku University School of Medicine, Miyagi, Japan.
Sugimoto
T
T
Kohri
K
K
Hidaka
H
H
Hattori
E
E
Yamamoto
H
H
Yonekura
H
H
Okamoto
H
H
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D015139:Blotting, Southern; D002645:Chickens; D004247:DNA; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010191:Pancreatic Polypeptide / Q000235:genetics*; D011498:Protein Precursors / Q000235:genetics*; D016415:Sequence Alignment; D014158:Transcription, Genetic
C043710:PPY protein, human; D011498:Protein Precursors; D010191:Pancreatic Polypeptide; D004247:DNA