Nuclear Protein, Ataxia Telangiectasia Locus (NPAT)

NPAT lies only 0.5 kb from the 5-prime end of the ATM gene and is transcribed in the opposite direction as ATM. NPAT encodes a 1,427-amino acid protein containing nuclear localization signals and target sites for phosphorylation by cyclin-dependent protein kinases associated with E2F. NPAT has a calculated molecular mass of 154,300 Da. It is relatively serine and threonine rich. The mRNA of NPAT was detected in all human tissues examined and its genomic sequence was strongly conserved through eukaryotes, suggesting that the NPAT gene may be essential for cell maintenance, i.e., a housekeeping gene. The promoter region may be shared by ATM and NPAT and that each gene may influence the expression of the other.