The ZPR1 gene is highly conserved in mammals and yeast. The sequences of the human, mouse, and yeast (S. pombe and S. cerevisiae) ZPR1 proteins were compared using the PILE-UP program (version 7.2; Wisconsin Genetics Computer Group, Madison, WI). Residues that are identical with human ZPR1 are indicated with a period. Gaps were introduced to optimize the alignment (–). The two zinc fingers are overlined, and the Cys residues are indicated with asterisks. The sequence of mouse ZPR1 (GenBank accession number U41287) has been reported (Galcheva-Gargova et al., 1996). The human and yeast ZPR1 protein sequences were deduced from the nucleotide sequence of HeLa cDNA clones isolated from a λZAP II phage library (Stratagene) and from the sequence of yeast genomic clones. The sequences of the human ZPR1 cDNA, the S. pombe zpr1+ gene, and the S. cerevisiae ZPR1 gene have been deposited in GenBank with accession numbers AF019767, AF019768, and AF019769, respectively.