| First Author | Ressl S | Year | 2015 |
| Journal | Structure | Volume | 23 |
| Issue | 4 | Pages | 688-99 |
| PubMed ID | 25752542 | Mgi Jnum | J:247438 |
| Mgi Id | MGI:5927365 | Doi | 10.1016/j.str.2015.01.019 |
| Citation | Ressl S, et al. (2015) Structures of C1q-like proteins reveal unique features among the C1q/TNF superfamily. Structure 23(4):688-99 |
| abstractText | C1q-like (C1QL) -1, -2, and -3 proteins are encoded by homologous genes that are highly expressed in brain. C1QLs bind to brain-specific angiogenesis inhibitor 3 (BAI3), an adhesion-type G-protein coupled receptor that may regulate dendritic morphology by organizing actin filaments. To begin to understand the function of C1QLs, we determined high-resolution crystal structures of the globular C1q-domains of C1QL1, C1QL2, and C1QL3. Each structure is a trimer, with each protomer forming a jelly-roll fold consisting of 10 beta strands. Moreover, C1QL trimers may assemble into higher-order oligomers similar to adiponectin and contain four Ca(2+)-binding sites along the trimeric symmetry axis, as well as additional surface Ca(2+)-binding sites. Mutation of Ca(2+)-coordinating residues along the trimeric symmetry axis lowered the Ca(2+)-binding affinity and protein stability. Our results reveal unique structural features of C1QLs among C1q/TNF superfamily proteins that may be associated with their specific brain functions. |
