5′-Rapid amplification of cDNA ends analysis (RACE)
Total RNA was isolated from A3.01 T cells using RNeasy mini kit (Qiagen). The transcriptional start sites of A3G were identified using the 5′/3′ RACE Kit, 2nd Generation (Roche) according to the manufacturer's instructions. The following primers were used: RACE-APO3G1 (5′-TATCCCTTGTACACTTTGT-3′) for cDNA synthesis, RACE-APO3G2 (5′-CATACTCCTGGTCACGAT-3′) for the first PCR and RACE-APO3Gnest (5′-GAATACACCTGGCCTCGAA-3′) for the nested PCR. Reaction products were analyzed by agarose gel electrophoresis, purified using QIAquick gel extraction kit (Qiagen), T/A-cloned into vector pCR4-TOPO (Invitrogen) and sequenced.