HSP90 alpha Recombinant Protein

The protein encoded by this gene is an inducible molecular chaperone that functions as a homodimer. The encoded protein aids in the proper folding of specific target proteins by use of an ATPase activity that is modulated by co-chaperones. Two transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jan 2012]

Function: 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. Ref.15 Ref.22 Ref.28

Subunit structure: Homodimer. Identified in NR3C1/GCR steroid receptor-chaperone complexes formed at least by NR3C1, HSP90AA1 and a variety of proteins containing TPR repeats such as FKBP4, FKBP5, PPID, PPP5C STIP1. Interacts with AHSA1, FNIP1, HSF1, SMYD3 and TOM34. Interacts with TERT; the interaction, together with PTGES3, is required for correct assembly and stabilization of the TERT holoenzyme complex. Interacts with CHORDC1 and DNAJC7. Interacts with STUB1 and UBE2N; may couple the chaperone and ubiquitination systems. Interacts (via TPR repeat-binding motif) with PPP5C (via TPR repeats); the interaction is direct and activates PPP5C phosphatase activity. Ref.17 Ref.18 Ref.19 Ref.20 Ref.22 Ref.23 Ref.24 Ref.25 Ref.26 Ref.27 Ref.28 Ref.31 Ref.40 Ref.43 Ref.50 Ref.51

Subcellular location: Cytoplasm. Melanosome. Note: Identified by mass spectrometry in melanosome fractions from stage I to stage IV. Ref.42

Domain: The TPR repeat-binding motif mediates interaction with TPR repeat-containing proteins like the co-chaperone STUB1.

Post-translational modification: ISGylated. Ref.41S-nitrosylated; negatively regulates the ATPase activity and the activation of eNOS by HSP90AA1.

Sequence similarities: Belongs to the heat shock protein 90 family.