S100A10 (4E7E10) Mouse mAb #5529

Despite their relatively small size (8-12 kDa) and uncomplicated architecture, S100 proteins regulate a variety of cellular processes, such as cell growth and motility, cell cycle progression, transcription, and differentiation. To date, 25 members have been identified, including S100A1-S100A18, trichohyalin, filaggrin, repetin, S100P, and S100Z, making it the largest group in the EF-hand, calcium-binding protein family. Interestingly, 14 S100 genes are clustered on human chromosome 1q21, a region of genomic instability. Research studies have demonstrated that significant correlation exists between aberrant S100 protein expression and cancer progression. S100 proteins primarily mediate immune responses in various tissue types but are also involved in neuronal development (1-4).

Each S100 monomer bears two EF-hand motifs and can bind up to two molecules of calcium (or other divalent cation in some instances). Structural evidence shows that S100 proteins form antiparallel homo- or heterodimers that coordinate binding partner proximity in a calcium-dependent (and sometimes calcium-independent) manner. Although structurally and functionally similar, individual members show restricted tissue distribution, are localized in specific cellular compartments, and display unique protein binding partners, which suggests that each plays a specific role in various signaling pathways. In addition to an intracellular role, some S100 proteins have been shown to act as receptors for extracellular ligands or are secreted and exhibit cytokine-like activities (1-4).

S100A10 (alternately known as p11 or calpactin 1 light chain) forms a constitutive heterotetramer with annexin A2 (ANXA2) and may act as a bridge between the plasma membrane and actin cytoskeleton via interactions with the plasma membrane (via ANXA2) and various protein partners such as the SNARE complex or actin (5-7). S100A10 has been hypothesized to play a critical role in neuronal signaling due to its interaction and regulation of neurotransmitter receptors and neuron-specific ion channels such as 5-HT1B, TRPV5, ASIC1, TASK1, and NaV1.8 (8-10). More recently, S100A10 has also been shown to modulate macrophage activation and invasion via its ability to bind and transmit receptor-like signals in response to plasminogen (11,12).