Sialic Acid Modification of Adiponectin Is Not Required for Multimerization or Secretion but Determines Half-Life in Circulation
Ayanthi A Richards, Michelle L Colgrave, Jialiang Zhang, Julie Webster, Fiona Simpson, Elaine Preston, Donna Wilks, Kyle L Hoehn, Matthew Stephenson, Graeme A Macdonald, John B Prins, Gregory J Cooney, Aimin Xu, Jonathan P Whitehead
MOLECULAR ENDOCRINOLOGY | ENDOCRINE SOC | Published : 2010
Adiponectin is an adipocyte-secreted, insulin-sensitizing hormone the circulating levels of which are reduced in conditions of insulin resistance and diabetes. Previous work has demonstrated the importance of posttranslational modifications, such as proline hydroxylation and lysine hydroxylation/glycosylation, in adiponectin oligomerization, secretion, and function. Here we describe the first functional characterization of adiponectin sialylation. Using a variety of biochemical approaches we demonstrated that sialylation occurs on previously unidentified O-linked glycans on Thr residues of the variable domain in human adiponectin. Enzymatic removal of sialic acid or its underlying O-linked s..View full abstract
This work was supported by grants from the National Health and Medical Research Council of Australia ( to J.P.W., G. A. M., and J.B.P.), the National Heart Foundation ( to J.P.W.), and the Diabetes Australia Research Trust ( to A. A. R.).