Differential conservation of transcriptional domains of mammalian Prophet of Pit-1 proteins revealed by structural studies of the bovine gene and comparative functional analysis of the protein.
The Prophet of Pit-1 (PROP1) gene encodes a paired class homeodomain transcription factor that is exclusively expressed in the developing mammalian pituitary gland. PROP1 function is essential for anterior pituitary organogenesis, and heritable mutations in the gene are associated with combined pituitary hormone deficiency in human patients and animals. By cloning the bovine PROP1 gene and by comparative analysis, we demonstrate that the homeodomains and carboxyl termini of mammalian PROP1 proteins are highly conserved while the amino termini are diverged. Whereas the carboxyl termini of the human and bovine PROP1 proteins contain potent transcriptional activation domains, the amino termini and homeodomains have repressive activities. The bovine PROP1 gene has four exons and three introns and maps to a region of chromosome seven carrying a quantitative trait locus affecting ovulation rate. Two alleles of the bovine gene were found that encode distinct protein products with different DNA binding and transcriptional activities. These experiments demonstrate that mammalian PROP1 genes encode proteins with complex regulatory capacities and that modest changes in protein sequence can significantly alter the activity of this pituitary developmental transcription factor.
Showalter
Aaron D
AD
Department of Biology, Indiana University-Purdue University Indianapolis, 723 West Michigan Street, Indianapolis IN 46202-5132, USA.
Smith
Timothy P L
TP
Bennett
Gary L
GL
Sloop
Kyle W
KW
Whitsett
Julie A
JA
Rhodes
Simon J
SJ
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites / Q000235:genetics; D002417:Cattle / Q000235:genetics*; D002460:Cell Line; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D017124:Conserved Sequence / Q000235:genetics; D004247:DNA / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D010060:Ovulation / Q000235:genetics; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D018398:Homeodomain Proteins; C102134:Prophet of Pit-1 protein; D020033:Protein Isoforms; D004247:DNA