Serum amyloid A

Serum amyloid A

protein
Name = Human Serum amyloid A1
caption =


width =
HGNCid = 10513
Symbol = SAA1
AltSymbols =
EntrezGene = 6288
OMIM = 104750
RefSeq = NM_199161
UniProt = P02735
PDB =
ECnumber =
Chromosome = 11
Arm = p
Band = 15.1
LocusSupplementaryData = protein
Name = Human Serum amyloid A2
caption =


width =
HGNCid = 10514
Symbol = SAA2
AltSymbols =
EntrezGene = 6289
OMIM = 104751
RefSeq = NM_030754
UniProt = P02735
PDB =
ECnumber =
Chromosome = 11
Arm = p
Band = 15.1-p14
LocusSupplementaryData = protein
Name = Human Serum amyloid A3, pseudogene
caption =


width =
HGNCid = 10515
Symbol = SAA3P
AltSymbols = SAA3
EntrezGene = 6290
OMIM =
RefSeq =
UniProt = P22614
PDB =
ECnumber =
Chromosome = 11
Arm = p
Band = 15.1-p14
LocusSupplementaryData = protein
Name = Human Serum amyloid A4
caption =


width =
HGNCid = 10516
Symbol = SAA4
AltSymbols = C-SAA
EntrezGene = 6291
OMIM = 104752
RefSeq = NM_006512
UniProt = P35542
PDB =
ECnumber =
Chromosome = 11
Arm = p
Band = 15.1-p14
LocusSupplementaryData =

Serum amyloid A (SAA) proteins are a family of apolipoproteins associated with high-density lipoprotein (HDL) in plasma. Different isoforms of SAA are expressed constitutively (constitutive SAAs) at different levels or in response to inflammatory stimuli (acute phase SAAs). These proteins are predominantly produced by the liver. [cite journal |author=Uhlar CM, Whitehead AS |title=Serum amyloid A, the major vertebrate acute-phase reactant |journal=Eur. J. Biochem. |volume=265 |issue=2 |pages=501–23 |year=1999 |pmid=10504381 |doi= |url=http://www.blackwell-synergy.com/openurl?genre=article&sid=nlm:pubmed&issn=0014-2956&date=1999&volume=265&issue=2&spage=501] The conservation of these proteins throughout invertebrates and vertebrates suggests SAAs play a highly essential role in all animals. [cite journal |author=Manley PN, Ancsin JB, Kisilevsky R |title=Rapid recycling of cholesterol: the joint biologic role of C-reactive protein and serum amyloid A |journal=Med. Hypotheses |volume=66 |issue=4 |pages=784–92 |year=2006 |pmid=16337748 |doi=10.1016/j.mehy.2005.10.018 |url=]

Acute phase serum amyloid A proteins

Acute phase serum amyloid A proteins (A-SAAs) are secreted during the acute phase of inflammation. These proteins have several roles, including the transport of cholesterol to the liver for secretion into the bile, the recruitment of immune cells to inflammatory sites and the induction of enzymes that degrade extracellular matrix. A-SAAs are implicated in several chronic inflammatory diseases, such as amyloidosis, atherosclerosis, and rheumatoid arthritis.cite journal |author=Zhang N, Ahsan MH, Purchio AF, West DB |title=Serum amyloid A-luciferase transgenic mice: response to sepsis, acute arthritis, and contact hypersensitivity and the effects of proteasome inhibition |journal=J. Immunol. |volume=174 |issue=12 |pages=8125–34 |year=2005 |pmid=15944321 |doi= |url=http://www.jimmunol.org/cgi/pmidlookup?view=long&pmid=15944321] Three acute phase SAA isoforms have been reported in mice, called SAA1, SAA2 and SAA3. During inflammation, SAA1 and SAA2 are principally expressed and induced in the liver, while SAA3 is induced in many distinct tissues. SAA1 and SAA2 genes are regulated in liver cells by the proinflammatory cytokines IL-1, IL-6, and TNF-α. Both SAA1 and SAA2 are induced up to a 1000-fold in mice under acute inflammatory conditions following exposure to bacterial lipopolysaccharide (LPS). Three A-SAA genes have also been identified in humans [cite journal |author=Betts JC, Edbrooke MR, Thakker RV, Woo P |title=The human acute-phase serum amyloid A gene family: structure, evolution and expression in hepatoma cells |journal=Scand. J. Immunol. |volume=34 |issue=4 |pages=471–82 |year=1991 |pmid=1656519 |doi= |url=] , although the third gene, "SAA3", is believed to represent a pseudogene that does not generate messenger RNA or protein. [cite journal |author=Kluve-Beckerman B, Drumm ML, Benson MD |title=Nonexpression of the human serum amyloid A three (SAA3) gene |journal=DNA Cell Biol. |volume=10 |issue=9 |pages=651–61 |year=1991 |pmid=1755958 |doi= |url=]

Constitutive serum amyloid A proteins

A fourth SAA (SAA4) was identified in humans and is expressed constitutively in the liver thus is defined as a constitutive SAA (C-SAA). [cite journal |author=Steel DM, Sellar GC, Uhlar CM, Simon S, DeBeer FC, Whitehead AS |title=A constitutively expressed serum amyloid A protein gene (SAA4) is closely linked to, and shares structural similarities with, an acute-phase serum amyloid A protein gene (SAA2) |journal=Genomics |volume=16 |issue=2 |pages=447–54 |year=1993 |pmid=7686132 |doi=10.1006/geno.1993.1209 |url=] A similar protein has since been identified in the mouse that is now also called SAA4; it had originally been designated SAA5. [cite journal |author=de Beer MC, Kindy MS, Lane WS, de Beer FC |title=Mouse serum amyloid A protein (SAA5) structure and expression |journal=J. Biol. Chem. |volume=269 |issue=6 |pages=4661–7 |year=1994 |pmid=8308037 |doi= |url=http://www.jbc.org/cgi/pmidlookup?view=long&pmid=8308037] [cite journal |author=de Beer MC, de Beer FC, Gerardot CJ, "et al" |title=Structure of the mouse Saa4 gene and its linkage to the serum amyloid A gene family |journal=Genomics |volume=34 |issue=1 |pages=139–42 |year=1996 |pmid=8661036 |doi=10.1006/geno.1996.0253 |url=]

References


Wikimedia Foundation. 2010.

Игры ⚽ Нужно решить контрольную?

Look at other dictionaries:

  • serum amyloid — In secondary amyloidosis the fibrils deposited in tissues are unrelated to immunoglobulin light chains (in contrast to the situation in primary amyloidosis) and are made of amyloid A protein (AA protein). This is derived from serum amyloid A… …   Dictionary of molecular biology

  • Serum amyloid P component — Amyloid P component, serum (SAP) is the identical serum form of amyloid P component (AP), a 25kDa pentameric protein first identified as the pentagonal constituent of in vivo pathological deposits called amyloid .cite journal | author = Cathcart… …   Wikipedia

  • serum amyloid P-component — Precursor of amyloid component P, found in basement membrane. Member of the pentraxin family. See serum amyloid …   Dictionary of molecular biology

  • serum amyloid A protein — a high molecular weight protein synthesized in the liver; it is an acute phase protein and circulates in association with a subclass of HDL lipoproteins. It is the precursor to AA amyloid and accumulates in inflammation. Called also SAA p …   Medical dictionary

  • Amyloid — Amyloids are insoluble fibrous protein aggregates sharing specific structural traits. Abnormal accumulation of amyloid in organs may lead to amyloidosis, and may play a role in various other neurodegenerative diseases. Definition controversyThe… …   Wikipedia

  • amyloid — Glycoprotein deposited extracellularly in tissues in amyloidosis. The glycoprotein may either derive from light chain of immunoglobulin (AIO (amyloid of immune origin): 5 18 kD glycoprotein; product of a single clone of plasma cells, the N… …   Dictionary of molecular biology

  • amyloid A — AA amyloid a pathological fibrillar low molecular weight protein formed by cleavage of serum amyloid A (SAA) protein. It is deposited in the tissues secondary to chronic inflammatory conditions; see AA amyloidosis, under amyloidosis …   Medical dictionary

  • SAA protein — serum amyloid A p …   Medical dictionary

  • SAA2 — Serum amyloid A2, also known as SAA2, is a human gene. [cite web | title = Entrez Gene: SAA2 Serum amyloid A2| url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene Cmd=ShowDetailView TermToSearch=6289| accessdate = ] PBB Summary section title …   Wikipedia

  • SAA1 — Serum amyloid A1, also known as SAA1, is a human gene.cite web | title = Entrez Gene: SAA1 serum amyloid A1| url = http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene Cmd=ShowDetailView TermToSearch=6288| accessdate = ] PBB Summary section title =… …   Wikipedia

Share the article and excerpts

Direct link
… Do a right-click on the link above
and select “Copy Link”