Abstract
Heat shock can induce either cytoprotective mechanisms or cell death. We found that in certain human and mouse cells, including spermatocytes, activated heat shock factor 1 (HSF1) binds to sequences located in the intron(s) of the PMAIP1 (NOXA) gene and upregulates its expression which induces apoptosis. Such a mode of PMAIP1 activation is not dependent on p53. Therefore, HSF1 not only can activate the expression of genes encoding cytoprotective heat shock proteins, which prevents apoptosis, but it can also positively regulate the proapoptotic PMAIP1 gene, which facilitates cell death. This could be the primary cause of hyperthermia-induced elimination of heat-sensitive cells, yet other pro-death mechanisms might also be involved.
Highlights
All organisms have developed mechanisms to protect themselves from damage during cellular stress
We show that following heat shock the Pmaip1 gene becomes directly induced by Heat shock factor 1 (HSF1) leading to apoptosis in heat-sensitive cells
Using a genome-wide ChIP-Seq approach we found that HSF1 became localized in the second intron of the Pmaip1 gene in the chromatin of heat-shocked mouse spermatocytes [34]
Summary
All organisms have developed mechanisms to protect themselves from damage during cellular stress (e.g., heat shock). Damaged cells are either repaired or eliminated to keep the integrity of the organism. Either cytoprotection or programmed cell death can be induced in response to stress [1, 2]. Heat shock factor 1 (HSF1) is the primary transcription factor activated by different forms of proteotoxic stress. It becomes activated by forming trimers, which in turn bind to heat shock elements. These authors contributed : Patryk Janus, Agnieszka TomaJonik
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
