Complement Component 1, Q Subcomponent Like Protein 2 (C1qL2)

The insulin-sensitizing hormone, adiponectin, belongs to the expanding C1q/TNF family of proteins. In contrast, placenta and eye expressed the highest levels of CTRP6 and CTRP10 transcripts respectively.Like adiponectin, all secreted CTRP proteins form trimers as their basic structural units. CTRP3, CTRP5, CTRP6 and CTRP10 trimers are further assembled into higher-order oligomeric complexes via disulfide bonding mediated by their N-terminal cysteine residues. Besides forming homo-oligomers, CTRP1/CTRP6, CTRP2/CTRP7 and adiponectin/CTRP2 are secreted as heterotrimers, thus providing a mechanism to potentially generate functionally distinct ligands. Functional characterization of one such family member, CTRP1, showed that it specifically activates Akt and p44/42-MAPK signalling pathways in differentiated mouse myotubes.