Serum Amyloid P Component

Serum amyloid P component (SAP) is the identical serum form of amyloid P component (AP), a highly preserved plasma protein named for its ubiquitous presence in amyloid deposits. As a normal plasma protein first identified as the pentagonal constituent of in vivo pathological deposits called "amyloid". Serum amyloid P component represents another member of the pentraxin family, a highly conserved group of molecules that may play a role in innate immunity. SAP is a key negative regulator for innate immune responses to DNA and may be partly responsible for the insufficient immune responses after DNA vaccinations in humans. SAP suppression may be a novel strategy for improving efficacy of human DNA vaccines and requires further clinical investigations.

Serum Amyloid P Component Related Areas

Immunology>>Innate Immunity>>Acute Phase Proteins>>Serum Amyloid P Component/SAP

Serum Amyloid P Component Alternative Names

APCS, SAP, PTX2, MGC88159 [Homo sapiens]

Apcs, Sap [Mus musculus]

Summaries for Serum Amyloid P Component

Entrez Gene summary for Serum Amyloid P Component:

The protein encoded by APCS gene is a glycoprotein, belonging to the pentraxin family of proteins, which has a characteristic pentameric organization. These family members have considerable sequence homology which is thought to be the result of gene duplication. The binding of the encoded protein to proteins in the pathological amyloid cross-beta fold suggests its possible role as a chaperone. This protein is also thought to control the degradation of chromatin. It has been demonstrated that this protein binds to apoptotic cells at an early stage, which raises the possibility that it is involved in dealing with apoptotic cells in vivo. [provided by RefSeq, Sep 2008]

Wikipedia summary for 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". APCS is its human gene.

Human Serum Amyloid P Component Protein General Information

 

• Protein names: Serum amyloid P-component
  Short name=SAP
• Sequence length: 223 AA.
• Domain: Signal
• Sequence similarities: Belongs to the pentaxin family.
  Contains 1 pentaxin domain.
• Post-translational modification: N-glycosylated with a complex biantennary oligosaccharide chain with a sialic acid at the end (disialo-SAP). Monosialo-SAP as well as asioalo-SAP are also detected
• Subunit structure: Homopentamer. Pentaxin (or pentraxin) have a discoid arrangement of 5 non-covalently bound subunits.
• Subcellular location: Secreted.
• Tissue specificity: Found in serum and urine.
• Involvement in disease: Note=SAP is a precursor of amyloid component P which is found in basement membrane and associated with amyloid deposits.
• Cofactor: Binds 2 calcium ions per subunit.
• Mass spectrometry: Molecular mass is 25462.5±1.1 Da from positions 20 - 223. Determined by ESI.
  Molecular mass is 25463±3 Da from positions 20 - 223. Determined by MALDI.
  Molecular mass is 1285.78 Da from positions 213 - 223. Determined by MALDI.
  Molecular mass is 1186.71 Da from positions 213 - 222. Determined by MALDI.

General information above from UniProt

Function for Serum Amyloid P Component Protein

UniProtKB:

Serum amyloid P component can interact with DNA and histones and may scavenge nuclear material released from damaged circulating cells. Serum Amyloid P Component may also function as a calcium-dependent lectin.

Genatlas:

• Serum amyloid P component may be interacting with DNA and histones and may be scavenging nuclear material released from damaged circulating cells

Homology for human Serum Amyloid P Component

• homolog to rattus Apcs (71.17 pc)
• homolog to murine Apcs (68.92 pc)

Phenotype Information for Serum Amyloid P Component

• Gene/Locus: APCS, SAP
• Phenotype: { Amyloidosis, secondary, susceptibility to}

Phenotype Information for Serum Amyloid P Component from OMIM (Online Mendelian Inheritance in Man)