Induction of human mammary-associated serum amyloid A3 expression by prolactin or lipopolysaccharide.
In most mammalian species, serum amyloid A isoform 3 (SAA3) appears to be the predominant SAA isoform expressed extrahepatically. However, human SAA3 gene expression has not been detected previously and, therefore, this gene was referred to as a pseudogene. We report for the first time the transcriptional expression of human SAA3. Human SAA3 gene expression was detected by RT-PCR after stimulation of mammary gland epithelial cells with either prolactin (PRL) or lipopolysaccharide (LPS). The full-length 655bp cDNA sequence for this mammary-associated serum amyloid A3 (M-SAA3) was obtained using 5' and 3' rapid amplification of cDNA ends (RACE). The human M-SAA3 transcript would conceptually translate into a 42 residue mature protein, which is smaller than other mammalian SAA3 isoforms that are typically 104-113 amino acids in length. This study defines the cDNA sequence for human SAA3 and also demonstrates the upregulation of M-SAA3 expression in response to the lactational hormone PRL or to an acute phase stimulant such as LPS.
Larson
Marilynn A
MA
Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE 68198, USA.
Wei
Shu H
SH
Weber
Annika
A
Weber
Allen T
AT
McDonald
Thomas L
TL
D001483:Base Sequence; D001940:Breast / Q000187:drug effects* / Q000378:metabolism*; D002460:Cell Line; D017931:DNA Primers / Q000235:genetics; D018076:DNA, Complementary / Q000235:genetics; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism; D005260:Female; D015870:Gene Expression / Q000187:drug effects; D006801:Humans; D008070:Lipopolysaccharides / Q000494:pharmacology*; D008969:Molecular Sequence Data; D011388:Prolactin / Q000494:pharmacology*; D020033:Protein Isoforms / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D000685:Serum Amyloid A Protein / Q000235:genetics*
D017931:DNA Primers; D018076:DNA, Complementary; D008070:Lipopolysaccharides; D020033:Protein Isoforms; C489625:SAA3P protein, human; D000685:Serum Amyloid A Protein; D011388:Prolactin