HABP1/C1QBP: Proteins and Enzymes

Hyaluronan binding protein 1 (HABP1), also known as C1qBP/C1qR and p32, is a ubiquitous acidic glycoprotein that functions in spermatogenesis and as a receptor for proinflammatory molecules. HABP1 binds extracellular hyaluronan, vitronectin, complement component C1q, HMW kininogen, and bacterial and viral proteins. Intracellular HABP1 binds to molecules containing the C1q globular domain, multiple isoforms of PKC, mitochondrial Hrk, adrenergic and GABA-A receptors, the mRNA splicing factor ASF/SF2, and the CBF transcription factor.