Transcriptional regulation of human establishment of cohesion 1 homolog 2 ( ESCO2), the causative gene of Roberts syndrome, was investigated. Deletion and mutation analyses of the ESCO2 promoter indicated that the selenocysteine tRNA-activating factor (Staf) binding site (SBS) is an essential element for transcriptional activation of ESCO2. Electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assay revealed that the zinc finger protein 143 (ZNF143), a human homolog of Xenopus Staf, bound to the ESCO2 promoter. The ACTACAN submotif, adjacent to SBS, also contributed to transcriptional activation of ESCO2. EMSA indicated that the ACTACAN submotif was not involved in binding of ZNF143 to SBS. S phase-specific expression of the ESCO2 gene was confirmed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR), but EMSA revealed binding of ZNF143 to SBS in G1/S and G2/M phases. These results demonstrated that SBS functioned as the basal transcriptional activator of the S phase-specific gene ESCO2, but other mechanisms are required for cell cycle-dependent expression.