Canonical heat shock element in the αB-crystallin gene shows tissue- specific and developmentally controlled interactions with heat shock factor

Abstract

Oligomerization of the heat shock factor (HSF) and its interaction with the heat shock element (HSE) are the hallmark of active transcriptional response to tangible physical or chemical stress. It is unknown if these interactions are subject to control and modulation by developmental cues and thus have tissue or stage specificity. By using promoter sequences containing a canonical HSE from the αB-crystallin gene, we demonstrate a tissue- specific transition from monomeric (in fetal and early neonatal stages that lack oligomeric HSF-HSE complexes) to oligomeric HSF-HSE interactions by postnatal day 10-21 in the ocular lens. Developmental control of these interactions is further demonstrated by induction of oligomeric HSF-HSE complexes in neonatal extracts by in vitro manipulations, interestingly, only in the lens and not in the brain, heart, or liver extracts. The exclusive presence of oligomeric HSF-HSE complexes in the postnatal/adult lens corresponds to known highly increased number of αB-crystallin transcripts in this tissue.