Stress-induced-phosphoprotein 1 (STIP1)
The protein contains 543 amino acids for an estimated molecular weight of 62639 Da.
Acts as a co-chaperone for HSP90AA1 (PubMed:27353360). Mediates the association of the molecular chaperones HSPA8/HSC70 and HSP90 (By similarity). (updated: Nov. 22, 2017)
Protein identification was indicated in the following studies:
- Goodman and co-workers. (2013) The proteomics and interactomics of human erythrocytes. Exp Biol Med (Maywood) 238(5), 509-518.
- Lange and co-workers. (2014) Annotating N termini for the human proteome project: N termini and Nα-acetylation status differentiate stable cleaved protein species from degradation remnants in the human erythrocyte proteome. J Proteome Res. 13(4), 2028-2044.
- Hegedűs and co-workers. (2015) Inconsistencies in the red blood cell membrane proteome analysis: generation of a database for research and diagnostic applications. Database (Oxford) 1-8.
- Wilson and co-workers. (2016) Comparison of the Proteome of Adult and Cord Erythroid Cells, and Changes in the Proteome Following Reticulocyte Maturation. Mol Cell Proteomics. 15(6), 1938-1946.
- Bryk and co-workers. (2017) Quantitative Analysis of Human Red Blood Cell Proteome. J Proteome Res. 16(8), 2752-2761.
- D'Alessandro and co-workers. (2017) Red blood cell proteomics update: is there more to discover? Blood Transfus. 15(2), 182-187.
- Chu and co-workers. (2018) Quantitative mass spectrometry of human reticulocytes reveal proteome-wide modifications during maturation. Br J Haematol. 180(1), 118-133.
Methods
The following articles were analysed to gather the proteome content of erythrocytes.
The gene or protein list provided in the studies were processed using the ID mapping API of Uniprot in September 2018. The number of proteins identified and mapped without ambiguity in these studies is indicated below.
Only Swiss-Prot entries (reviewed) were considered for protein evidence assignation.
| Publication | Identification 1 | Uniprot mapping 2 | Not mapped / Obsolete | TrEMBL | Swiss-Prot |
|---|---|---|---|---|---|
| Goodman (2013) | 2289 (gene list) | 2278 | 53 | 20599 | 2269 |
| Lange (2014) | 1234 | 1234 | 7 | 28 | 1224 |
| Hegedus (2015) | 2638 | 2622 | 0 | 235 | 2387 |
| Wilson (2016) | 1658 | 1528 | 170 | 291 | 1068 |
| d'Alessandro (2017) | 1826 | 1817 | 2 | 0 | 1815 |
| Bryk (2017) | 2090 | 2060 | 10 | 108 | 1942 |
| Chu (2018) | 1853 | 1804 | 55 | 362 | 1387 |
1 as available in the article and/or in supplementary material
2 uniprot mapping returns all protein isoforms as one entry
The compilation of older studies can be retrieved from the Red Blood Cell Collection database.
The data and differentiation stages presented below come from the proteomic study and analysis performed by our partners of the GReX consortium, more details are available in their published work.
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The reference OMIM entry for this protein is 605063
Stress-induced phosphoprotein 1; stip1
Sti1, yeast, homolog of
Hsp70/hsp90-organizing protein; hop
DESCRIPTION
STIP1 is an adaptor protein that coordinates the functions of HSP70 (see HSPA1A; 140550) and HSP90 (see HSP90AA1; 140571) in protein folding. It is thought to assist in the transfer of proteins from HSP70 to HSP90 by binding both HSP90 and substrate-bound HSP70. STIP1 also stimulates the ATPase activity of HSP70 and inhibits the ATPase activity of HSP90, suggesting that it regulates both the conformations and ATPase cycles of these chaperones (Song and Masison, 2005).CLONING
By microsequencing a protein that was upregulated in transformed embryonic lung fibroblasts and using degenerate PCR primers to screen a transformed embryonic lung fibroblast cDNA library, Honore et al. (1992) obtained a cDNA encoding STIP1. The predicted 543-amino acid hydrophilic protein contains a tetratricopeptide repeat (TPR), a 34-amino acid motif that is repeated at least 6 times in STIP1. STIP1 is homologous to the yeast stress-inducible mediator of the heat shock response, Sti1. Western blot analysis and 2-dimensional gel electrophoresis showed that STIP1 was expressed as an approximately 61-kD protein. Northern blot analysis showed that STIP1, which was expressed as an approximately 2.1-kb transcript, was upregulated in transformed cell lines and psoriatic keratinocytes. Immunofluorescence analysis showed that STIP1 localized to the Golgi in normal fibroblasts, but mainly to the nucleus in transformed cells.GENE FUNCTION
Using mutation analysis, Chen and Smith (1998) localized a putative HSP90-binding domain to a central tetratricopeptide repeat (TPR) of the HOP sequence, and a putative HSP70-binding domain to an N-terminal TPR. Using in vitro steroid receptor assembly reactions, they found that reactions performed with HOP carrying mutations in the putative HSP70- and HSP90-binding domains resulted in receptor complexes that failed to incorporate HSP90. Chen and Smith (1998) concluded that HOP acts as an adaptor that directs HSP90 to preexisting HSP70-progesterone receptor complexes. By mutating the TPR regions of yeast Sti1, Song and Masison (2005) identified separate domains involved in the regulation of Hsp70 and Hsp90. All Sti1 mutations impaired protein folding, which required both Hsp70 and Hsp90. Human HOP1 complemented a yeast strain lacking Sti1, suggesting conservation of HSP70 and HSP90 regulation. Arruda-Carvalho et al. (2007) stated that STI1 is an extracellular protein that modulates cell death and differentiation through interaction with prion protein (PRNP; 176640). They treated rat retinal explants with mouse Sti1 or with neutralizing antibody and identified both Prnp-dependent and -independent roles for Sti1 in ganglion and neuroblastic cell death and differentiation. Canalization, or developmental robustness, is an organism's ability to produce the same phenotype despite genotypic variations and environmental influences. Expression of a gain-of-function allele of Drosophila Kruppel results in misregulation of genes in the fly eye disc and generation of eye outgrowths, which are normally repressed via canalization. Using a fly eye outgrowth assay, Gangaraju et al. (2011) showed that a protein complex made up of Piwi (see 605571), Hsp83 (HSP90), and Hop was involved in canalization. The results suggested that canalization may involve Hsp83-mediated phosphorylation of Piwi. Gangaraju et al. (2011) concluded that the eye outgrowth phenotype is a defect in epigenetic silencing of a normally supp ... More on the omim web site
Feb. 10, 2018: Protein entry updated
Automatic update: Entry updated from uniprot information.
Feb. 2, 2018: Protein entry updated
Automatic update: Uniprot description updated
Dec. 19, 2017: Protein entry updated
Automatic update: Uniprot description updated
March 16, 2016: Protein entry updated
Automatic update: OMIM entry 605063 was added.
Jan. 25, 2016: Protein entry updated
Automatic update: model status changed