Calcium-binding protein. Binds one calcium ion per monomer (PubMed:17030513). Can promote differentiation of adipocytes (in vitro). Overexpression in 3T3-L1 preadipocytes increases their proliferation, enhances adipogenesis and reduces insulin-stimulated glucose uptake (PubMed:21266506, PubMed:23526364). Homodimer (PubMed:17030513). Interacts with TP53 (PubMed:21266506). Primarily nucleolar. A high intracellular calcium level induces nucleolar exit and nucleocytoplasmic transport, whereas a low intracellular calcium level leads to nuclear translocation and accumulation within specific region of nucleoli (PubMed:17030513). Ubiquitous (PubMed:17030513). Widely distributed throughout the adult brain and predominantly expressed within specific astrocyte populations (PubMed:17030513). Expressed at high level in adipose tissues of obese animals (PubMed:21266506). S100A16 proteins, but not other S100 proteins, have only one functional Ca(2+) binding site per monomer (PubMed:14684152, PubMed:17030513). Upon Ca(2+) binding, undergoes conformational changes leading to the exposure of hydrophobic patches which could be implicated in the Ca(2+)-dependent nuclear export. Binds Zn(2+) (PubMed:17030513). Ca(2+) and Zn(2+) do not bind to the same site (PubMed:17030513). Does not bind Cu(2+) (PubMed:17030513). Belongs to the S-100 family.