Nuclear Location Bias of HCAR1 Drives Cancer Malignancy through Numerous Routes [RNA-seq]

The involvement of G-Protein-Coupled Receptors' (GPCR) location bias in diverse cellular functions and their misregulation in pathology is an underexplored territory. HCAR1, a GPCR for lactate is linked to cancer progression, mainly due to Warburg effect, but its mechanism of action remains elusive. Here, we show HCAR1 has a nuclear localization, capable of signaling intranuclearly to induce nuclear-ERK and AKT phosphorylation concomitant with higher cancer cell proliferation and survival. We determine its nuclear interactome, proving its involvement in protein-translation and DNA-damage repair. Nuclear HCAR1 (N-HCAR1) directly interacts with chromatin/DNA promoting expression of genes involved in cellular migration. Notably, we show N-HCAR1 particularly regulates a broader transcriptomic signature than its PM counterpart, emphasizing on the facts that functional output of N-HCAR1 is larger than PM localized HCAR1. Our study presents several unprecedented processes by which a GPCR through location-biased activity regulate various cellular functions and how cancer cells exploit these. Overall design: RNAseq of HeLa cells transfected with shRNA (scr = shScrambled, b = shHCAR1b and dl = KD+dS305A) with a lentiviral shRNA against HCAR1 targeting 3'UTR regions of the gene. Transfected Hela cells were treated with either PBS (P) or lactate (L), representing six conditions, with 3 to 5 biological replicates per condition.