Complement component 1 Q subcomponent-binding protein, mitochondrial (C1QBP), a member of the MAM33 family, is also known as ASF/SF2-associated protein p32, glycoprotein gC1qBP (C1qBP), mitochondrial matrix protein p32 and hyaluronan-binding protein 1, which is a homotrimer that contains three monomers forming a donut-shaped structure with an unusually asymmetric charge distribution on the surface. C1q associates with C1r and C1s in order to yield the first component of the serum complement system. C1QBP has also been identified as the p32 subunit of pre-mRNA splicing factor SF2, as well as a hyaluronic acid-binding protein. Furthermore, C1QBP has been shown to interact with Protein kinase D1, BAT2, PRKCD, PKC alpha and Protein kinase Mζ .