The function of ZNF143 (zinc finger protein 143, Ensembl gene identifier ENSG00000166478) is as follows. Transcription factor that activates expression of genes transcribed by both RNA polymerases II and III, and which is required to safeguard mitochondrial activity (PubMed:10893243, PubMed:14702349, PubMed:17938208, PubMed:26416877, PubMed:39708803, PubMed:9705341, PubMed:9776743). Specifically recognizes and binds the Staf-binding site (SBS), a consensus DNA-binding motif present in thousands of promoters (PubMed:17092945, PubMed:21177654, PubMed:23408857, PubMed:9705341). Activates the gene for selenocysteine tRNA (tRNAsec) (PubMed:23152058). Activates expression of small nuclear RNA (snRNA) transcribed by RNA polymerases II and III (PubMed:17938208, PubMed:9776743). Also activates expression of mRNAs and acts as a key regulator of cell proliferation and differentiation by specifically activating expression of a subset of nuclear-encoded mitochondrial genes, thereby controlling mitochondrial function (By similarity). Involved in the maintenance of embryonic stem cells by promoting association of POU5F1/OCT4 to promoters, leading to NANOG expresion (By similarity). {ECO:0000250|UniProtKB:O70230, ECO:0000269|PubMed:10893243, ECO:0000269|PubMed:14702349, ECO:0000269|PubMed:17092945, ECO:0000269|PubMed:17938208, ECO:0000269|PubMed:21177654, ECO:0000269|PubMed:23152058, ECO:0000269|PubMed:23408857, ECO:0000269|PubMed:26416877, ECO:0000269|PubMed:39708803, ECO:0000269|PubMed:9705341, ECO:0000269|PubMed:9776743}.