Complement component 1 Q subcomponent-binding protein (C1QBP) (C1QBP)

Complement component 1 Q subcomponent-binding protein (C1QBP), also known as p32 or gC1qR, is a multifunctional protein that localizes to the mitochondria, nucleus, and cell surface [1, 4, 11]. It is essential for mitochondrial oxidative phosphorylation, where it acts as a chaperone to support the translation of respiratory chain subunits [1, 12]. C1QBP also functions as a cell surface receptor for ligands such as C1q and kininogen, influencing immune responses and inflammation [4, 11]. In many cancers, C1QBP is significantly overexpressed and correlates with poor patient outcomes by promoting tumor growth, metastasis, and resistance to apoptosis [5, 15, 16]. Experimental therapies, including the small molecule M36 and the peptide LyP-1, target C1QBP to disrupt mitochondrial metabolism and inhibit mitogenic signaling pathways like Akt-mTOR [12, 14, 16]. Despite its potential as a target, the ubiquitous expression of C1QBP and its vital role in cardiac function pose risks for systemic toxicity and cardiomyopathy [1, 2].

Other names

p32gC1qRHABP1Hyaluronan-binding protein 1SF2-associated protein p32Mitochondrial matrix protein p32gC1q-RSF2P32GC1QBPP33COXPD33

Inhibition of mitochondrial oxidative phosphorylation, induction of ubiquitin-dependent protein degradation, blocking of cell surface receptor interactions, and inhibition of mitogenic signaling pathways such as Akt-mTOR and MAPK.