Published Paper Details:

Calnexin is an ER resident protein with calcium binding ability. It has known functions in glycoprotein folding and maturation. Cumulative evidences indicate the implication of calnexin in apoptosis induced by ER stress. Calnexin gene silencing in lung cancer cell line was shown to decrease cancer cell survival leading to effective chemotherapy. MAR binding protein SMAR1, established to have both tumor suppressor as well as immuno-modulatory functions. We speculated that apart from its tumor suppressor function, SMAR1 might also be involved in immunosurveillance of cancer cells. Earlier results depicted that SMAR1 increases the enrichment of both GATA2 and HDAC1 at calnexin promoter that they might interact with each other and form a repressor complex. However, no reports are available showing its interaction with HDAC1. SMAR1 is known to interact with HDAC1, but its interaction with GATA2 is unknown. We hypothesize that SMAR1 might form a triple complex with GATA2 and HDAC1 resulting in deacetylation of GATA2. We then checked the interaction between SMAR1, GATA2 and HDAC1. GATA2 Acts as an Activator of Calnexin in the Absence of SMAR1. GATA2 is known to act as an activator under acetylated condition, this acetylation is generally carried out by p300, an important member of HAT family of proteins. We try to establish that SMAR1 forms a triple complex with GATA2 and HDAC1. In the presence of SMAR1, there is reduction in acetylation of GATA2. So, we further want to check how SMAR1 and HDAC1 helps in the weak acetylation of GATA2.