S100A9

(redirected from Calgranulin b)

S100A9

A gene on chromosome 1q21 that encodes a member of the S100 family of proteins, which contain 2 EF-hand calcium-binding motifs and as a group regulate cell cycle progression and differentiation and other cellular processes. S100A9 has antimicrobial activity against bacteria and fungi and provides resistance to invasion by pathogenic bacteria, and it upregulates transcription of genes under the control of NF-kappa-B; it is linked to the endotoxic shock response to bacterial lipopolysaccharide. S100A9 promotes tubulin polymerisation and macrophage and granulocyte migration and infiltration into wound sites; it is a pro-inflammatory mediator and upregulates IL8 release and cell surface expression of ICAM1. Extracellular S100A9 (calprotectin) binds to target cells and promotes apoptosis.
 
Molecular pathology
Altered expression of S100A9 is linked to cystic fibrosis.
References in periodicals archive ?
Additionally, this technique provided a possible protein identification for the previously unidentified band (Figure 2, band 3) and the small SELDI-TOF peak at 13,000 (Figure 1B), calgranulin B.
Two readily observable peaks, seen only in spectra from the diesel-exposed, 24-hr samples, represent anaphylatoxin C3a and calgranulin A, and a third peak, whose signal is only slightly above noise, is also present only in spectra from exposed, 24-hr samples and was identified as calgranulin B.
Subsequent analysis using LC/MS indicates that the proteins producing these peaks are calgranulin A, calgranulin B, and anaphylatoxin C3a.
Anaphylatoxin C3a, a component of the complement system, is a well-known mediator of inflammation [see Ember and Hugli (1997) for a review], and calgranulin A is a part of a hetero-dimer with calgranulin B (also known as MRP-8 and MRP-14, respectively) that make up calprotectin.