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Crystal structure of N-terminal domain of Hsp90 from Dictyostelium discoideum
Structural highlights
FunctionHSC90_DICDI Molecular chaperone that promotes the maturation, structural maintenance and proper regulation of specific target proteins involved for instance in cell cycle control and signal transduction. Undergoes a functional cycle that is linked to its ATPase activity. This cycle probably induces conformational changes in the client proteins, thereby causing their activation. Interacts dynamically with various co-chaperones that modulate its substrate recognition, ATPase cycle and chaperone function (By similarity). Publication Abstract from PubMedCytosolic heat shock protein 90 (Hsp90) has been implicated in diverse biological processes such as protein folding, cell cycle control, signal transduction, development, and morphological evolution. Model systems available for studying Hsp90 function either allow ease of manipulation for biochemical studies or facilitate a phenomenological study of its role in influencing phenotype. In this work, we have explored the use of the cellular slime mold Dictyostelium discoideum to examine cellular functions of Hsp90 in relation to its multicellular development. In addition to cloning, purification, biochemical characterization, and examination of its crystal structure, our studies, using a pharmacological inhibitor of Hsp90, demonstrate a role for the cytoplasmic isoform (HspD) in D. discoideum development. Inhibition of HspD function using geldanamycin (GA) resulted in delayed aggregation and arrest of D. discoideum development at the 'mound' stage. Crystal structure of the amino-terminal domain of HspD showed a binding pocket similar to that described for yeast Hsp90. Fluorescence spectroscopy, as well as GA-coupled beads affinity pulldown, confirmed a specific interaction between HspD and GA. The results presented here provide an important insight into the function of HspD in D. discoideum development and emphasize the potential of the cellular slime mold to serve as an effective model for studying the many roles of Hsp90 at cellular and organismal levels. Heat shock protein 90 regulates development in Dictyostelium discoideum.,Sawarkar R, Roy N, Rao S, Raman S, Venketesh S, Suguna K, Tatu U J Mol Biol. 2008 Oct 31;383(1):24-35. doi: 10.1016/j.jmb.2008.08.006. Epub 2008, Aug 7. PMID:18718841[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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