Varying intertrial interval reveals temporally defined memory deficits andenhancements in NTAN1-deficient mice

The N-end rule is one ubiquitin-proteolytic pathway that relates the in viv o half-life of a protein to the identity of its N-terminal residue. NTAN1 d eamidates N-terminal asparagine to aspartate, which is conjugated to argini ne by ATE1. An N-terminal arginine-bearing substrate protein is recognized, ubiquitylated by UBR1/E3 alpha, and subsequently degraded by 26S proteasom es. Previous research showed that NTAN1-deficient mice exhibited impaired l ong-term memory in the Lashley III maze. Therefore, a series of studies, de signed to assess the role of NTAN1 in short- and intermediate-term memory p rocesses, was undertaken. Two hundred sixty mice (126 -/-; 134 +/+) receive d Lashley III maze training with intertrial intervals ranging from 2-180 mi n. Results indicated that inactivation of NTAN1 amidase differentially affe cts short-, intermediate-, and long-term memory.