The 712562 hTRT polypeptide (SEQ. ID NO: 10 [FIG. 19]) contains motifs T, 1, 2, and A, but not motifs B???, C, D and E. Similarly, a variant hTRT polypeptide with therapeutic and other activities may be expressed from a nucleic acid similar to the pGRN121 cDNA but lacking the 182 basepairs missing in clone 712562, e.g., having the sequence SEQ. ID. NO.: 4.