Expression of new members of the prolactin growth hormone gene family in bovine placenta. Isolation and characterization of two prolactin-like cDNA clones.
Two prolactin-like proteins (bPLP-I and bPLP-II) were deduced from the nucleotide sequence analyses of the cDNA clones derived from a bovine (Bos taurus) term placenta. These proteins resembled bovine prolactin but were different from the reported bovine placental lactogens or prolactin-related proteins. The predicted amino acid sequences of these clones showed 45-51% identity with bovine prolactin and 23-24% with bovine growth hormone. The two new clones show 62 and 39% overall homology with each other at the levels of nucleotide and amino acid sequences, respectively. bPLP-I, bPLP-II, placental lactogens, prolactins (PRLs), and other prolactin-like proteins isolated from cow, mouse, and rat share 7 common amino acid residues. Five of the 7 residues are conserved by other members of the family such as growth hormones, suggesting that they may be essential for the common structural features of the gene family. The other 2 residues are uniquely conserved in bovine, mouse, and rat placental lactogens, PRLs, and PRL-like proteins, predicting their indispensable roles in binding to the specific receptors. bPLP-I and bPLP-II, as well as bPLP-III, are shown to be expressed stage specifically and predominantly in full-term bovine placentas.
Yamakawa
M
M
Department of Biochemistry, Mie University School of Medicine, Japan.
Tanaka
M
M
Koyama
M
M
Kagesato
Y
Y
Watahiki
M
M
Yamamoto
M
M
Nakashima
K
K
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D003001:Cloning, Molecular; D004247:DNA / Q000235:genetics; D015342:DNA Probes; D005260:Female; D015870:Gene Expression; D015723:Gene Library; D013006:Growth Hormone / Q000235:genetics*; D008969:Molecular Sequence Data; D005810:Multigene Family; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011388:Prolactin / Q000235:genetics*; D011487:Protein Conformation; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid
D015342:DNA Probes; D011388:Prolactin; D013006:Growth Hormone; D004247:DNA