The Human Acute‐Phase Serum Amyloid A Gene Family: Structure, Evolution and Expression in Hepatoma Cells

  title={The Human Acute‐Phase Serum Amyloid A Gene Family: Structure, Evolution and Expression in Hepatoma Cells},
  author={Joanna C. Betts and Mark R. Edbrooke and Rajesh V. Thakker and Patricia Woo},
  journal={Scandinavian Journal of Immunology},
Serum amyloid A (SAA) proteins are a group of phylogenetically conserved acute‐phase reactants. Evidence is presented here for the existence of four genetic loci for the human serum amyloid A (SAA) genes. The first locus was defined by three contiguous γ clones spanning =: 30 kb which contained a single SAA gene encoding apoSAA1β. Allelic variants were isolated at (he second locus: a novel clone encoding apoSAA2α was distinguished from SAA2β (previously known as SAAg9, Ref. 1) by a His/Arg… 
Structure of the Mouse Serum Amyloid A 5 (Saa5) Gene: Relationship to Other Members of the Serum Amyloid A Family
Sequencing of the constitutively expressed mouse Saa5 gene revealed a 4 exon/3 intron structure, with a B2 repeat located ≈450 base pairs upstream, and a microsatellite contained within intron 2.
Tissue specific expression of serum amyloid A.
Results indicate that as with other liver specific proteins tissues specific expression o f SAA is due to multiple elements incuding C/EBP an, in SAA2, an as of yet unidentified element which the ubiquitously expressed transcription factor Y Y l may be a component.
Serum amyloid A, the major vertebrate acute-phase reactant.
Although the precise role of A-SAA in host defense during inflammation has not been defined, many potential clinically important functions have been proposed for individual SAA family members, including involvement in lipid metabolism/transport, induction of extracellular-matrix-degrading enzymes, and chemotactic recruitment of inflammatory cells to sites of inflammation.
Extrahepatic production of acute phase serum amyloid A.
There is growing evidence that extrahepatic A-SAA formation may play a crucial role in amyloidogenesis and enhancesAmyloid formation at the site of SAA production.
Expression and function of serum amyloid A, a major acute-phase protein, in normal and disease states
The importance of SAA in various physiological and pathological processes, including inflammation, atherosclerosis, thrombosis, AA-amyloidosis, rheumatoid arthritis, and neoplasia, is emphasized and new functions, affecting cell adhesion, migration, proliferation and aggregation are described.


Structure of the murine serum amyloid A gene family. Gene conversion.
Comparison of the upstream regions of the SAA genes with those of the rat fibrinogen genes, whose expression is also induced by inflammation, reveals sequences common to all six genes which are very improbable on a random basis.
Heterogeneity of human serum amyloid A protein. Five different variants from one individual demonstrated by cDNA sequence analysis.
The variability of the SAA gene family in one individual is investigated by sequencing 11 SAA-specific clones from an acute-phase-liver cDNA library, and at least five different SAA variants were deduced from six different cDNAs.
Human serum amyloid A. Three hepatic mRNAs and the corresponding proteins in one person.
Three separate SAA proteins have been isolated from the plasma of one individual and completely sequenced and it is proved that: (a) the often-reported absence of arginine at the amino terminus of S AA proteins must result from proteolytic processing of the protein; (b) the polymorphism involving histidine and arginin at position 71 is present at the DNA level and therefore is not due to an event at the translational level.
Human serum amyloid A (SAA): biosynthesis and postsynthetic processing of preSAA and structural variants defined by complementary DNA.
To study structural variants of human serum amyloid A (SAA), an apoprotein of high-density lipoprotein, complementary DNA clones were isolated from a human liver library with the use of two synthetic
Rat tissues express serum amyloid A protein-related mRNAs.
  • R. MeekE. Benditt
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1989
Rats do have representatives of the SAA gene family and express two distinct SAA mRNAs, and the pattern of genes expressed among tissues, and their induction by inflammatory agents, is similar to that of related mouse genes.
Human serum amyloid A protein. The assignment of the six major isoforms to three published gene sequences and evidence for two genetic loci.
The phenotypic expression of apo-SAA isoforms is rationalized with published apo's cDNA structures predicted from pA1 and pSAA82 and the genomic DNA SAAg9 to suggest that these isoforms are the products of genes which are allelic variants at a single locus distinct from that for the pI 6.0/6.4 isoform pair.
Transcriptional regulation of serum amyloid A gene expression.
A comparison of the rates of SAA gene transcription and SAA RNA accumulation suggests that SAA mRNA levels are regulated during the acute phase response by increased transcription and mRNA stabilization.
Structural diversity of murine serum amyloid A genes. Evolutionary implications.
Mouse serum amyloid A (SAA) gene family comprises four members that are closely linked in the chromosome 7. Two of these genes encoding major mouse SAA isotypes (SAA1 and SAA2) are highly homologous