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- *****************************
- * Pentaxin family signature *
- *****************************
-
- Pentaxins (or pentraxins) [1] are a family of proteins which show, under
- electron microscopy, a discoid arrangement of five noncovalently bound
- subunits. Proteins known to belong to this family are:
-
- - C-reactive protein (CRP), a protein which, in mammals, is expressed during
- acute phase response to tissue injury or inflammation. CRP displays several
- functions associated with host defense: it promotes agglutination,
- bacterial capsular swelling, phagocytosis and complement fixation through
- its calcium-dependent binding to phosphorylcholine. CRPs have also been
- sequenced [2] in an invertebrate, the Atlantic horseshoe crab, where they
- are a normal constituent of the hemolymph.
- - Serum Amyloid P-component (SAP), a precursor of amyloid component P which
- is found in basement membrane and is associated with amyloid deposits.
- - Hamster female protein (FP) [3], a plasma protein whose concentration is
- altered by sex steroids and stimuli that elicit an acute phase response.
- - Human PTX3 [4]. PTX3 is a cytokine-induced protein whose function is not
- yet known and which contains a pentaxin domain in its C-terminal half.
-
- The sequences of the different members of this family are quite conserved. As
- a signature, we selected a six residue pattern which includes a cysteine
- known to be involved in a disulfide bridge in CRPs and SAP.
-
- -Consensus pattern: H-x-C-x-[ST]-W-x-S
- -Sequences known to belong to this class detected by the pattern: ALL.
- -Other sequence(s) detected in SWISS-PROT: NONE.
- -Last update: October 1993 / Text revised.
-
- [ 1] Pepys M.B., Baltz M.L.
- Adv. Immunol. 34:141-212(1983).
- [ 2] Nguyen N.Y., Suzuki A., Boykins R.A., Liu T.-Y.
- J. Biol. Chem. 261:10456-10465(1986).
- [ 3] Dowton S.B., Woods D.E., Mantzouranis E.C., Colten H.R.
- Science 228:1206-1208(1985).
- [ 4] Breviario F., d'Aniello E.M., Golay J., Peri G., Bottazi B., Bairoch A.,
- Saccone S., Marzella R., Predazzi V., Rocchi M., Della Valle G.,
- Dejana E., Mantovani A., Introna M.
- J. Biol. Chem. 267:22190-22197(1992).
-