tRNA 2’-phosphotransferase 1(TRPT1) is a member of the KptA/TPT1 family. TRPT1 catalyzes the last step of tRNA splicing, the transfer of the splice junction 2’-phosphate from ligated tRNA to NAD to produce ADP-ribose 1’’-2’’ cyclic phosphate. TRPT1 is broadly expressed; it is weakly or not expressed in the lung, spleen, small intestine and peripheral blood leukocytes.