Heat shock protein HSP 90-beta - P08238 (HS90B_HUMAN)


Protein Feature View of PDB entries mapped to a UniProtKB sequence  

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 (PubMed:16478993, PubMed:19696785). Engages with a range of client protein classes via its interaction with various co-chaperone proteins or complexes, that act as adapters, simultaneously able to interact with the specific client and the central chaperone itself. Recruitment of ATP and co-chaperone followed by client protein forms a functional chaperone. After the completion of the chaperoning process, properly folded client protein and co-chaperone leave HSP90 in an ADP-bound partially open conformation and finally, ADP is released from HSP90 which acquires an open conformation for the next cycle (PubMed:27295069, PubMed:26991466). Apart from its chaperone activity, it also plays a role in the regulation of the transcription machinery. HSP90 and its co-chaperones modulate transcription at least at three different levels. In the first place, they alter the steady-state levels of certain transcription factors in response to various physiological cues. Second, they modulate the activity of certain epigenetic modifiers, such as histone deacetylases or DNA methyl transferases, and thereby respond to the change in the environment. Third, they participate in the eviction of histones from the promoter region of certain genes and thereby turn on gene expression (PubMed:25973397). Antagonizes STUB1-mediated inhibition of TGF-beta signaling via inhibition of STUB1-mediated SMAD3 ubiquitination and degradation (PubMed:24613385). Promotes cell differentiation by chaperoning BIRC2 and thereby protecting from auto-ubiquitination and degradation by the proteasomal machinery (PubMed:18239673). Main chaperone that is involved in the phosphorylation/activation of the STAT1 by chaperoning both JAK2 and PRKCE under heat shock and in turn, activates its own transcription (PubMed:20353823). UniProt
Pathway Maps
      ESCHER  BiGG
Subunit Structure
Monomer (PubMed:24880080). Homodimer (PubMed:7588731, PubMed:18400751). Forms a complex with CDK6 and CDC37 (PubMed:9482106, PubMed:25486457). Interacts with UNC45A; binding to UNC45A involves 2 UNC45A monomers per HSP90AB1 dimer (PubMed:16478993). Interacts with CHORDC1 (By similarity). Interacts with DNAJC7 (PubMed:18620420). Interacts with FKBP4 (PubMed:15159550). May interact with NWD1 (PubMed:24681825). Interacts with SGTA (PubMed:16580629). Interacts with HSF1 in an ATP-dependent manner. Interacts with MET; the interaction suppresses MET kinase activity. Interacts with ERBB2 in an ATP-dependent manner; the interaction suppresses ERBB2 kinase activity. Interacts with HIF1A, KEAP1 and RHOBTB2 (PubMed:26517842). Interacts with STUB1 and SMAD3 (PubMed:24613385). Interacts with XPO1 and AHSA1 (PubMed:22022502, PubMed:25486457). Interacts with BIRC2 (PubMed:25486457). Interacts with KCNQ4; promotes cell surface expression of KCNQ4 (PubMed:23431407). Interacts with BIRC2; prevents auto-ubiquitination and degradation of its client protein BIRC2 (PubMed:18239673). Interacts with NOS3 (PubMed:23585225). Interacts with AHR; interaction is inhibited by HSP90AB1 phosphorylation on Ser-226 and Ser-255 (PubMed:15581363). Interacts with STIP1 and CDC37; upon SMYD2-dependent methylation (PubMed:24880080). Interacts with JAK2 and PRKCE; promotes functional activation in a heat shock-dependent manner (PubMed:20353823). Interacts with HSP90AA1; interaction is constitutive (PubMed:20353823). HSP90AB1-CDC37 chaperone complex interacts with inactive MAPK7 (via N-terminal half) in resting cells; the interaction is MAP2K5-independent and prevents from ubiquitination and proteasomal degradation (PubMed:23428871). Interacts with CDC25A; prevents heat shock-mediated CDC25A degradation and contributes to cell cycle progression (PubMed:22843495). Interacts with TP53 (via DNA binding domain); suppresses TP53 aggregation and prevents from irreversible thermal inactivation (PubMed:15358771). Interacts with TGFB1 processed form (LAP); inhibits latent TGFB1 activation (PubMed:20599762). Interacts with TRIM8; prevents nucleus translocation of phosphorylated STAT3 and HSP90AB1 (By similarity). Interacts with NR3C1 (via domain NR LBD) and NR1D1 (via domain NR LBD) (By similarity). Interacts with PDCL3 (By similarity). Interacts with TTC4 (via TPR repeats) (PubMed:18320024). UniProt
The TPR repeat-binding motif mediates interaction with TPR repeat-containing proteins. UniProt
The Protein Feature View requires a browser that supports SVG (Scalable Vector Graphics). Mouse over tracks and labels for more information.
Data origin/color codes
The vertical color bar on the left side indicates data provenance.
Data in green originates from UniProtKB  
Variation data (sourced from UniProt) shows non-genetic variation from the ExPASy   and dbSNP   websites.
Data in yellow originates from Pfam  , by interacting with the HMMER3 web site  
Data in purple originates from Phosphosite  .
Data in orange originates from the SCOP   (version 1.75) and SCOPe   (version 2.04) classifications.
Data in grey has been calculated using BioJava  . Protein disorder predictions are based on JRONN (Troshin, P. and Barton, G. J. unpublished), a Java implementation of RONN  
  • Red: potentially disorderd region
  • Blue: probably ordered region.
Hydropathy has been calculated using a sliding window of 15 residues and summing up scores from standard hydrophobicity tables.
  • Red: hydrophobic
  • Blue: hydrophilic.
Data in lilac represent the genomic exon structure projected onto the UniProt sequence.
Data in blue originates from PDB
  • Secstruc: Secondary structure projected from representative PDB entries onto the UniProt sequence.
Sequence Mismatches It is now possible to see information about expression tags, cloning artifacts, and many other details related to sequence mismatches.
Icons represent a number of different sequence modifications that can be observed in PDB files. For example the 'T' icon T represents expression tags that have been added to the sequence. The 'E' icon E represents an engineered mutation. However, besides these two, there are many other icons. For more information about the meaning and exact position of a sequence modification, move the cursor over the icon.
Validation Track

For more details on the Validation Track (Structure Summary Page only) see the dedicated help page.

Data in red indicates combined ranges of Homology Models from the SWISS-MODEL Repository  
The PDB to UniProt mapping is based on the data provided by the EBI SIFTS project. See also Velankar et al., Nucleic Acids Research 33, D262-265 (2005).
Organism icons generated by flaticon.com under CC BY. The authors are: Freepik, Icons8, OCHA, Scott de Jonge.

For more details on the Protein Feature view see the dedicated help page.