Primary structure of human insulin-like growth factor-binding protein/placental protein 12 and tissue-specific expression of its mRNA.
The low-molecular-mass insulin-like growth factor-binding protein (IGF-BP) and placental protein 12 (PP12) are identical proteins that are present in human serum, amniotic fluid, secretory endometrium and decidua. IGF-BP/PP12 is believed to act as an autocrine or paracrine regulator of cell growth. A cDNA clone encompassing the entire protein coding region of this protein was isolated from a human decidual cDNA library. The authenticity of the cDNA was verified by in vitro transcription/translation experiments and by the identity of the 10 N-terminal amino acids deduced for the mature peptide with those obtained by direct protein sequencing. The amino acid sequence indicates that pre-IGF-BP/PP12 consists of 259 amino acid residues. The putative signal peptide is 25 residues long, and the mature protein thus contains 234 amino acids and has a molecular mass of 25293 Da. The sequence is very cysteine-rich at the N-terminus after which there are regions of clustered Pro, Glu, Ser and Thr residues (so-called PEST regions), which exist in proteins with short half-lives. The amino acid sequence also includes an Arg-Gly-Asp tripeptide that may function as a cell recognition signal. The IGF-BP/PP12 gene encodes a single 1.6 kb mRNA species that is expressed in decidua, secretory endometrium, liver and a human hepatoma cell line (HepG2). Southern blot analysis suggests that there is a single IGF-BP/PP12 gene in the human genome.
Julkunen
M
M
Population Council, New York, NY.
Koistinen
R
R
Aalto-Setälä
K
K
Seppälä
M
M
Jänne
O A
OA
Kontula
K
K
D000595:Amino Acid Sequence; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D003656:Decidua / Q000502:physiology; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1; D018969:Insulin-Like Growth Factor Binding Proteins; D008969:Molecular Sequence Data; D008970:Molecular Weight; D011257:Pregnancy Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D012995:Solubility; D014018:Tissue Distribution
D002352:Carrier Proteins; C032231:IGFBP1 protein, human; D018970:Insulin-Like Growth Factor Binding Protein 1; D018969:Insulin-Like Growth Factor Binding Proteins; D011257:Pregnancy Proteins; D012333:RNA, Messenger