"One of the proteins identified is Hsp83, a member of the highly conserved Hsp90 family including chaperones known to maintain the activity of many proteins"

"a fraction of the total Hsp90 pool is localized at the centrosome throughout the cell cycle at different stages of development in Drosophila and vertebrates"

"Disruption of Hsp90 function by mutations in the Drosophila gene or treatment of mammalian cells with the Hsp90 inhibitor geldanamycin, results in abnormal centrosome separation and maturation, aberrant spindles and impaired chromosome segregation"

"flies carrying a mutation for the heat-shock protein Hsp83 (Hsp83(08445)) showed exaggerated homeostatic response and died after sleep deprivation"

"activating heat-shock genes before sleep deprivation rescued cyc(01) flies from its lethal effects"

"Hsp82 (heat-shock protein 82) has been identified by MS as the main Rpn10/p54-interacting protein, suggesting its role in the reassembly of the 26 S proteasome after Zn2+ removal"

"removal of Zn2+ is followed by reassociation of subunit Rpn10/p54 to the RP, reassembly of the 26 S proteasome and resumption of the peptidase activity"

"stress proteins, including Hsp23, Hsp26, Hsp83 and Frost as well as membrane-associated proteins may contribute to the cold hardening response"

"increases in the levels of Hsp83 and DnaJ-1 proteins but not in the inducible form of Hsp70 were detected by Western blot analysis"

"the compensatory upregulation of constitutively expressed Hsps, in the absence of the synthesis of the major inducible Hsp, Hsp70, could still provide substantial thermoprotection"

"the Hsp90 chaperone (encoded by Hsp83 in Drosophila) is a localization factor for two mRNAs, nanos and pgc"

"levels of the LKB1 kinase are reduced in Hsp83 mutant egg chambers"

"NMNAT displays chaperone function both in biochemical assays and cultured cells, and it shares significant structural similarity with known chaperones"

"it is upregulated in the brain upon overexpression of poly-glutamine expanded protein and recruited with the chaperone Hsp70 into protein aggregates"

"isolated the product of the Hsp83 gene, the evolutionarily conserved chaperone Hsp90, as a specific component of the cap-binding complex"

"Hsp90 interacts in vitro with the translational repressor Cup"

"lowering Hsp90 activity enhances the oogenesis alterations linked to diverse cup mutant alleles"

"Hsp90 and Cup co-localize in the cytoplasm of the developing germ-line cells within the germarium"

"Hsp90 cooperates with Trx at chromatin for maintaining the active expression state of targets like the Hox genes"

"Pharmacological inhibition of Hsp90 results in degradation of Trx and a concomitant down-regulation of homeotic gene expression"

"we apply LOPIT, a mass-spectrometry based technique that simultaneously maps proteins to specific subcellular compartments, to Drosophila embryos"

"XPORT is a resident ER and secretory pathway protein that interacts with TRP and Rh1, as well as with Hsp27 and Hsp90"

"XPORT promotes the targeting of TRP to the membrane in Drosophila S2 cells"

"It localizes near promoters of many coding and noncoding genes including microRNAs"

"Hsp90 maintains and optimizes RNA polymerase II pausing via stabilization of the negative elongation factor complex (NELF)"

"Inhibition of Hsp90 leads to upregulation of target genes"

"unloaded AGO3 that localizes to cytoplasmic foci interacts with Hsp83"

"our genetic and cell biological data point toward an important role for the Hsp83 machinery in piRNA biogenesis"

"Hsp83 was enriched in a peri-nuclear rim, potentially reflecting nuage accumulation"

"Sicily preprotein interacts with cytosolic Hsp90 to chaperone the CI subunit, ND42, before mitochondrial import"

"Hsp90 binds to Sicily in an in vitro co-IP assay"

"flies expressing Hsp90 RNAi #1 exhibit severely decreased levels of Sicily, ND42, and NDUFS3 compared with controls"

"Mutation of Hsp83, the Drosophila homolog of mammalian Hsp90, results in increased E2F-dependent transcription and ectopic cell proliferation in pupal tissues at a time when neighboring wild-type cells are postmitotic"

"these Hsp83 mutant cells have increased Cyclin/Cdk activity and accumulate proteins normally targeted for proteolysis by the anaphase-promoting complex/cyclosome (APC/C)"

"we propose that Cdh1/Fzr is a client protein of Hsp83"

"a genome-wide fosmid library of 10000 GFP-tagged clones, comprising tagged genes and most of their regulatory information"

"a tetratricopeptide repeat (TPR) domain at the N-terminal end of Nup358 interacts with Hsp83 and is indispensable for Met nuclear localization"

"Nup358 facilitates JH-induced Met nuclear transport in a manner dependent on importin β and Hsp83"

"the Hsp90 system is required to extend the dwell time of Ago2 in the open state"

"Loading of small RNAs into Argonaute, the core protein in RNA silencing, requires the Hsp70/Hsp90 chaperone machinery"

"the Hsp70 system expands the structural ensembles of Ago2 and the Hsp90 system captures and stabilizes the active form"

"Hsp90 also has the ability to directly interact with and deform membranes via an evolutionarily conserved amphipathic helix"

"we structurally separated the Hsp90 membrane-deforming function from its well-characterized chaperone activity"

"mutations and drugs that stabilize the open Hsp90 dimer expose the helix and allow MVB fusion"

"Hsp83 is both necessary and sufficient for NSC reactivation by promoting the activation of InR pathway in larval brains in the presence of dietary amino acids"

"Both Hsp83 and its co-chaperone Cdc37 physically associate with InR"

"Mora localises to mitotic spindles and co-purifies with the Hsp90-R2TP-TTT supercomplex and with additional well-known Hsp90 co-chaperones"

"Drosophila Mora localises to mitotic spindles and co-purifies with the Hsp90-R2TP-TTT supercomplex"

"Cyp40 interacts with duplex-incorporating Ago2 through Hsp90 in vitro and selectively promotes the build-up of Ago2-bound miRNAs"

"these results identify RISC-regulatory roles for Hsp90 machinery"

"we isolated a protein complex composed of Hsp90, Piwi and Hop, the Hsp70/Hsp90 organizing protein homolog"

"Hsp90 and Hop regulate the piRNA pathway through Piwi to mediate canalization"

"epigenetic silencing of the expression of existing genetic variants and the suppression of transposon-induced new genetic variation as two major mechanisms underlying piRNA pathway-mediated canalization"

"Hsp83 is best understood as the **cytosolic Hsp90 ATP-dependent chaperone** that promotes **late-stage folding/maturation, stabilization, and activation** of diverse client proteins, especially those central to signaling and development (prodromou2022advancestowardsunderstanding pages 1-3, oostenhawle2023organismalrolesof pages 1-3). Mechanistically, Hsp90 proteins are **dimeric**, undergoing an **ATP-driven conformational cycle** involving **ATP binding/hydrolysis** and large structural rearrangements that enable remodeling/maturation of clients"

"Key named regulators include **Cdc37** (kinase client recruitment), **p23**, and **Aha1**, as well as **TPR-domain** proteins such as **Hop** that bind the conserved **MEEVD** C-terminal motif typical of cytosolic Hsp90s"

"A key Drosophila primary study demonstrated that the **ecdysone receptor heterodimer EcR/USP requires an Hsp83/Hsp90-containing multichaperone complex for activation**. Purified components—Hsp83 (Hsp90), Hsc70, Hop, Hip, FKBP52, and p23—were sufficient to reconstitute functional EcR/USP DNA binding in vitro, and activation required **ATP hydrolysis and Mg2+**"

"In Drosophila juvenile hormone signaling, Hsp83 physically interacts with the JH receptor **Methoprene-tolerant (Met)**, and JH increases the Met–Hsp83 interaction. Hsp83 loss-of-function attenuates JH binding and reduces JH-induced **nuclear import** of Met, decreasing JH-responsive transcription of **Kr-h1**"

"In Hsp83(6-55) mutant clones, E2F-dependent transcription increases and cells show ectopic S phase and mitosis after neighboring cells have exited the cell cycle"

"Phenotypically, **all stages of spermatogenesis involving microtubule function are affected**, from early mitotic divisions through sperm maturation and individualization/motility (yue1999geneticanalysisof pages 1-2). In a viable male-sterile allele (*scratch*), Hsp83/Hsp90 protein was reduced by **~3-fold** (ovaries, testes, male bodies), correlating with fully penetrant male sterility (yue1999geneticanalysisof pages 5-7). Biochemically, only a small fraction of Hsp83 co-purifies with taxol-stabilized microtubule proteins, and Hsp83 does not remain bound through repeated microtubule assembly/disassembly, supporting an **indirect role** via stabilization/maturation of microtubule effectors and/or signaling components rather than direct tubulin polymerization"

"Hsp83 also contributes to female fertility, oogenesis, and maternal RNA regulation. It interacts with the translational regulator Cup during oogenesis, localizes maternal transcripts, and affects *nanos* mRNA localization, linking Hsp83 to anterior–posterior patterning in embryos."

"Hsp83/Hsp90 buffers cryptic genetic variation and supports fitness in natural fly populations. Reduced Hsp83 expression from naturally occurring insertions lowers fecundity and longevity and weakens robustness, especially under inbreeding and mild heat stress, supporting the classic"

"A 2023 Nature Communications study in Drosophila larval fat body found that **Nacα reduction activates a heat shock response**, with upregulation of Hsp70/Hsp40 class genes and oxidative stress markers, but **Hsp83 (and another Hsp90-family gene Gp93) did not change** in that context (qRT-PCR, n=4 batches)"