Functions as a coactivator for aryl hydrocarbon and nuclear receptors (NR). Recruited to promoters through its contact with the N-terminal basic helix-loop-helix-Per-Arnt-Sim (PAS) domain of transcription factors or coactivators, such as NCOA2. During ER-activation acts synergistically in combination with other NCOA2-binding proteins, such as EP300, CREBBP and CARM1. Involved in the transcriptional activation of target genes in the Wnt/CTNNB1 pathway. Functions as a secondary coactivator in LEF1-mediated transcriptional activation via its interaction with CTNNB1. Coactivator function for nuclear receptors and LEF1/CTNNB1 involves differential utilization of two different activation regions. In association with CCAR1 enhances GATA1- and MED1-mediated transcriptional activation from the gamma-globin promoter during erythroid differentiation of K562 erythroleukemia cells (By similarity). Seems to enhance inorganic pyrophosphatase thus activating phosphogluomutase (PMG). Probably functions as component of the calphoglin complex, which is involved in linking cellular metabolism (phosphate and glucose metabolism) with other core functions including protein synthesis and degradation, calcium signaling and cell growth (By similarity). Part of a calphoglin complex consisting of CALCOCO1, PPA1 and PGM (By similarity). Interacts with the bHLH-PAS domains of GRIP1, AHR and ARNT. Interacts with CTNNB1 via both its N- and C-terminal regions. Interacts with EP300. Interacts with CCAR1 (via N-terminus) and GATA1 (By similarity). Shuttles between nucleus and cytoplasm. The C-terminal activation region (AD) is used for downstream signaling. Seems to be essential for coactivator function with nuclear receptors and with the aryl hydrocarbon receptor (By similarity). The N-terminal activation region (AD) is necessary and sufficient for synergistic activation of LEF1-mediated transcription by CTNNB1. Contains a EP3000 binding region which is important for synergistic cooperation (By similarity). Recruitment by nuclear receptors is accomplished by the interaction of the coiled-coiled domain with p160 coactivators. Belongs to the CALCOCO family.