Recombinant Mouse Protein S100-B (S100b)

Function

Small zinc- and- and calcium-binding protein that is highly expressed in astrocytes and constitutes one of the most abundant soluble proteins in brain (By similarity). Weakly binds calcium but binds zinc very tightly-distinct binding sites with different affinities exist for both ions on each monomer (By similarity). Physiological concentrations of potassium ion antagonize the binding of both divalent cations, especially affecting high-affinity calcium-binding sites (By similarity). Acts as a neurotrophic factor that promotes astrocytosis and axonal proliferation (PubMed:2592414, PubMed:8202493). Involved in innervation of thermogenic adipose tissue by acting as an adipocyte-derived neurotrophic factor that promotes sympathetic innervation of adipose tissue (PubMed:31043739). Binds to and initiates the activation of STK38 by releasing autoinhibitory intramolecular interactions within the kinase (By similarity). Interaction with AGER after myocardial infarction may play a role in myocyte apoptosis by activating ERK1/2 and p53/TP53 signaling (By similarity). Could assist ATAD3A cytoplasmic processing, preventing aggregation and favoring mitochondrial localization (By similarity). May mediate calcium-dependent regulation on many physiological processes by interacting with other proteins, such as TPR-containing proteins, and modulating their activity (By similarity)

Subcellular Location

Cytoplasm; Nucleus; Secreted

Subunit

Dimer of either two alpha chains, or two beta chains, or one alpha and one beta chain (By similarity). The S100B dimer binds two molecules of STK38 (By similarity). Interacts with CACYBP in a calcium-dependent manner (By similarity). Interacts with ATAD3A; this interaction probably occurs in the cytosol prior to ATAD3A mitochondrial targeting (By similarity). Interacts with S100A6 (By similarity). The S100B dimer interacts with two molecules of CAPZA1 (By similarity). Interacts with AGER (By similarity). Interacts with PPP5C (via TPR repeats); the interaction is calcium-dependent and modulates PPP5C activity (By similarity). Interacts with TPPP; this interaction inhibits TPPP dimerization (By similarity). Interacts with isoform CLSTN3beta of CLSTN3; interaction promotes secretion (PubMed:31043739)

• Jiang H. et al. Organization, sequence, and expression of the murine S100 beta gene. Transcriptional regulation by cell type-specific cis-acting regulatory elements. — J. Biol. Chem. (1993)
• The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC). — Genome Res. (2004)
• Huttlin E.L. et al. A tissue-specific atlas of mouse protein phosphorylation and expression. — Cell (2010)
• Winningham-Major F. et al. Neurite extension and neuronal survival activities of recombinant S100 beta proteins that differ in the content and position of cysteine residues. — J. Cell Biol. (1989)
• Reeves R.H. et al. Astrocytosis and axonal proliferation in the hippocampus of S100b transgenic mice. — Proc. Natl. Acad. Sci. U.S.A. (1994)
• Zeng X. et al. Innervation of thermogenic adipose tissue via a calsyntenin 3beta-S100b axis. — Nature (2019)