title: Evolutionarily conserved dual lysine motif determines the non-chaperone function of secreted Hsp90alpha in tumour progression.
abstract: Both intracellular and extracellular heat shock protein-90 (Hsp90) family proteins (α and β) have been shown to support tumour progression. The tumour-supporting activity of the intracellular Hsp90 is attributed to their N-terminal ATPase-driven chaperone function. What molecular entity determines the extracellular function of secreted Hsp90 and the distinction between Hsp90α and Hsp90β was unclear. Here we demonstrate that CRISPR/Case9 knocking out Hsp90α nullifies tumour cells' ability to migrate, invade and metastasize without affecting the cell survival and growth. Knocking out Hsp90β leads to tumour cell death. Extracellular supplementation with recombinant Hsp90α, but not Hsp90β, protein recovers tumourigenicity of the Hsp90α-knockout cells. Sequential mutagenesis identifies two evolutionarily conserved lysine residues, lys-270 and lys-277, in the Hsp90α subfamily that determine the extracellular Hsp90α function. Hsp90β subfamily lacks the dual lysine motif and the extracellular function. Substitutions of gly-262 and thr-269 in Hsp90β with lysines convert Hsp90β to a Hsp90α-like protein. Newly constructed monoclonal antibody, 1G6-D7, against the dual lysine region of secreted Hsp90α inhibits both de novo tumour formation and expansion of already formed tumours in mice. This study suggests an alternative therapeutic approach to target Hsp90 in cancer, that is, the tumour-secreted Hsp90α, instead of the intracellular Hsp90α and Hsp90β.
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Zou
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Bhatia
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.
authors.forename: H
authors.initials: H
authors.lastname: Dong
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.
authors.forename: P
authors.initials: P
authors.lastname: Jayaprakash
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.
authors.forename: J
authors.initials: J
authors.lastname: Guo
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.
authors.forename: D
authors.initials: D
authors.lastname: Sahu
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Hou
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.
authors.forename: F
authors.initials: F
authors.lastname: Tsen
authors.affiliation: Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research and Department of Cell and Neurobiology, Los Angeles, CA, USA.
authors.forename: C
authors.initials: C
authors.lastname: Tong
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.
authors.forename: K
authors.initials: K
authors.lastname: O'Brien
authors.affiliation: Department of Biochemistry and Molecular Biology and Zilkha Neurogenetic Institute University of Southern California Keck Medical Center, Los Angeles, CA, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Situ
authors.affiliation: Department of Biochemistry and Molecular Biology and Zilkha Neurogenetic Institute University of Southern California Keck Medical Center, Los Angeles, CA, USA.
authors.forename: T
authors.initials: T
authors.lastname: Schmidt
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.|Department of Medical Research, Greater Los Angeles Veterans Affairs Heath Care System, Los Angeles, CA, USA.
authors.forename: M
authors.initials: M
authors.lastname: Chen
authors.affiliation: Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research and Department of Cell and Neurobiology, Los Angeles, CA, USA.
authors.forename: Q
authors.initials: Q
authors.lastname: Ying
authors.affiliation: Department of Biochemistry and Molecular Biology and Zilkha Neurogenetic Institute University of Southern California Keck Medical Center, Los Angeles, CA, USA.
authors.forename: T S
authors.initials: TS
authors.lastname: Ulmer
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.|Department of Medical Research, Greater Los Angeles Veterans Affairs Heath Care System, Los Angeles, CA, USA.
authors.forename: D T
authors.initials: DT
authors.lastname: Woodley
authors.affiliation: Department of Dermatology and the Norris Comprehensive Cancer Center, Los Angeles, CA, USA.|Department of Medical Research, Greater Los Angeles Veterans Affairs Heath Care System, Los Angeles, CA, USA.
authors.forename: W
authors.initials: W
authors.lastname: Li
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology*; D064113:CRISPR-Cas Systems; D045744:Cell Line, Tumor; D018450:Disease Progression; D019143:Evolution, Molecular; D005260:Female; D055786:Gene Knockout Techniques; D018841:HSP90 Heat-Shock Proteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008239:Lysine / Q000235:genetics / Q000378:metabolism; D013329:Structure-Activity Relationship
chemical_list: D018841:HSP90 Heat-Shock Proteins; C533585:HSP90AA2P protein, human; C493165:HSP90AB1 protein, human; D008239:Lysine