Interaction of neuropeptide Y and Hsp90 through a novel peptide binding region.
Hsp90 is a molecular chaperone that binds and assists refolding of non-native and/or labile polypeptides and also bind various peptides. However, the rules of how Hsp90 recognizes substrates have not been well characterized. By surface plasmon resonance measurements, a physiologically active peptide, neuropeptide Y (NPY), with a strong binding property to Hsp90 was identified from screening of 38 randomly selected peptide candidates. We showed that the carboxy-terminal fragment of NPY (NPY13-36), which forms an amphipathic alpha-helix structure, preserved the strong binding to Hsp90. Immunoprecipitation and immunoblotting using HeLa cell extracts revealed that newly synthesized NPY precursors bound to Hsp90, suggesting that the in vitro binding experiments identified an interactive peptide in vivo. Proteolytic cleavage of the NPY13-36/Hsp90 complex, as well as binding site analysis using deletion mutants of Hsp90, revealed the NPY binding locus on Hsp90alpha as the 192 amino acid region following the N-terminal domain. By electron microscopic analysis using an anti-Hsp90 antibody against the sequence proximal to the highly charged region, we showed that the Hsp90 dimer bound to NPY13-36 at both ends. Mutation of arginine residues in NPY13-36 to alanine abrogated binding to Hsp90. Our studies indicate that the hinge region after the N-terminal domain of Hsp90 and the positive charges on NPY are important for this interaction.
Ishiwatari-Hayasaka
Haruko
H
Department of Cell Biology, The Tokyo Metropolitan Institute of Medical Science, Tokyo 113-8613, Japan. hh9m@virginia.edu
Maruya
Mikako
M
Sreedhar
Amere Subbarao
AS
Nemoto
Takayuki K
TK
Csermely
Peter
P
Yahara
Ichiro
I
D000595:Amino Acid Sequence; D000818:Animals; D018841:HSP90 Heat-Shock Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000737:chemistry* / Q000378:metabolism*; D010446:Peptide Fragments / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism / Q000648:ultrastructure; D011485:Protein Binding / Q000235:genetics; D011498:Protein Precursors / Q000737:chemistry / Q000378:metabolism / Q000648:ultrastructure; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion; D055672:Static Electricity; D013329:Structure-Activity Relationship; D020349:Surface Plasmon Resonance; D013552:Swine; D014162:Transfection
D018841:HSP90 Heat-Shock Proteins; D009478:Neuropeptide Y; D010446:Peptide Fragments; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins