Human S100A9 Protein Is Stabilized by Inflammatory Stimuli via the Formation of Proteolytically-Resistant Homodimers

• DOI: 10.1371/journal.pone.0061832
• Publication Date: 2013-04-23T21:50:02Z
• Authors: Matteo Riva; Zhifei He; Eva Källberg; Fredrik Ivars; Tomas Leanderson
• Keywords: S100A9; S100A8; HEK 293 cells

S100A8 and S100A9 are Ca2+-binding proteins that associated with acute chronic inflammation cancer. They form predominantly heterodimers even if there data supporting homodimer formation. We investigated the stability of heterodimer in myeloid S100A8/S100A9 over-expressing COS cells. In both cases, were not completely degraded 48 hrs after blocking protein synthesis. contrast, single transfected cells, was 24 h, while unstable. However, expression rescued upon co-expression or inhibition proteasomal activity. Furthermore, S100A9, but S100A8, could be stabilized by LPS, IL-1β TNFα treatment. Interestingly, stimulation S100A9-transfected cells inhibitor lead to formation protease resistant homodimers. summary, our indicated is extremely unstable can inflammatory stimuli, via proteolytically The homodimers this mechanism may constitute an amplification step during reaction.