Spermidine/Spermine N1-Acetyltransferase 1 (SAT1)

SAT1 belongs to the acetyltransferase family, and is a rate-limiting enzyme in the catabolic pathway of polyamine metabolism. It catalyzes the acetylation of spermidine and spermine, and is involved in the regulation of the intracellular concentration of polyamines and their transport out of cells. Defects in this gene are associated with keratosis follicularis spinulosa decalvans (KFSD). All species below vertebrates had 1 copy of SSAT, whereas most all vertebrate species had functional SAT1 and SAT2 genes, with the exception of chicken and Xenopus. Northern blot and EST analysis indicated that SAT1 was expressed at higher levels than SAT2 and in a wider range of tissues. Whereas SAT1 showed a much greater preference for spermidine than spermine, SAT2 showed similar preference for the 2 polyamines.