The predicted RoRet and NPT3 and NPT4 proteins are similar to the 52-kD Ro/SSA auto-antigen and sodium phosphate transporter protein NPT1, respectively. (A) Alignment of the predicted amino acid sequence of the RoRet gene to the 52-kD Ro/SSA auto-antigen protein. The asterisks (*) under the alignment represent conserved amino acids, the dots represent conservative amino acid substitutions. The putative DNA-binding cysteine-rich domain and the B30-2 exon domain are boxed. The sequence of the RoRet cDNA has been deposited in GenBank, accession no. U90547. (B) Alignment of the predicted amino acid sequence of the two novel putative sodium phosphate transport proteins to that of the NPT1. Boxed are four potential transmembrane domains known to be conserved between human NPT1 and its rabbit homolog (Chong et al. 1993). The sequences of the NPT3 and NPT4 cDNAs has been deposited in GenBank, accession nos. U90544 and U90545, respectively.
