UBE2A/B is the trans-acting factor mediating mechanotransduction and contact inhibition.

Abstract

Mechanotransduction and contact inhibition (CI) control gene expression to regulate proliferation, differentiation, and even tumorigenesis of cells. However, their downstream trans-acting factors (TAFs) are not well known due to a lack of a high-throughput method to quantitatively detect them. Here, we developed a method to identify TAFs on the cis-acting sequences that reside inopen chromatin or DNase I-hypersensitive sites (DHSs) and to detect nucleocytoplasmic shuttling TAFs using computational and experimental screening. The DHS-proteomics revealed over 1,000 potential mechanosensing TAFs and UBE2A/B (Ubiquitin-conjugating enzyme E2 A) was experimentally identified as a force- and CI-dependent nucleocytoplasmic shuttling TAF. We found that translocation of YAP/TAZ and UBE2A/B are distinctively regulated by inhibition of myosin contraction, actin-polymerization, and CI depending on cell types. Next generation sequence analysis revealed many downstream genes including YAP are transcriptionally regulated by ubiquitination of histone by UBE2A/B. Our results suggested a YAP-independent mechanotransduction and CI pathway mediated by UBE2A/B.