Acts as coactivator of MAFF transcriptional activity. Inhibits cell growth and colony-forming efficiency. Interacts with MIS18A. Interacts (via its coiled-coil region) with MAFF. Interaction with MAFF induces its translocation from the cytoplasm to the nucleolus. Strongly expressed in brain, kidney and ovary. Moderately expressed in liver, spleen, thymus, prostate, testis, small intestine and colon. Weakly expressed in heart, placenta, lung and leukocytes. Belongs to the tektin family.