Induction of Vγ-Jγ rearrangements by E2A or HEB in the presence of RAG1 and RAG2.

(A) Schematic diagram of the human TCRG locus. The humanTCRG locus comprises 2 constant region gene segments (Cγ) preceded by 2 or 3 joining gene segments (Jγ) and at least 14 variable gene segments (Vγ) belonging to 4 subgroups. Nine Vγ gene segments (5 functional genes and 4 pseudogenes) belong to subgroup I, whereas subgroups II, III, and IV each consist of a single gene segment designated Vγ9, Vγ10, and Vγ11, respectively. Two pseudogenes, VγA and VγB, located upstream of Vγ9 and Vγ11, respectively, belong to none of these subgroups. Five joining segments have been identified: Jγ1.1, Jγ1.2, and Jγ1.3 upstream of Cγ1; and Jγ2.1 and Jγ2.3 upstream of Cγ2. In addition to the 6 functional Vγ gene segments (solid blocks), 3 pseudogenes (shaded blocks) can also rearrange to Jγ gene segments. (B) Following transfection of BOSC 23 cells, PCR amplification with 200 ng genomic DNA of the transfected cells was performed by means of VγI-3′– and Jγ1.3/2.3-3′–specific primers. Thymus DNA and BOSC 23 DNA were used as positive and nonspecific template controls, respectively. Electrophoresis of PCR products on 2% agarose gels shows that E47 or HEB and RAG1 plus RAG2 proteins can promote VγI-Jγ1.3/2.3 rearrangements at high levels as compared with transfectants expressing RR only (lane RR) as quantitated by RQ TaqMan PCR analysis.