TEL-Jak2 constructs. The various TEL-Jak2 constructs that were used in this study. TEL-Jak2 JH1 corresponds to TEL (amino acids 1-154) fused to the JH1 domain of Jak2 (amino acids 846-1129). The TEL▵PNT construct fuses TEL deleted in amino acids (65-116) to the Jak2 JH1 domain (amino acids 846-1129). TEL-Jak2 JH2 encompasses a fusion of TEL (1-154) to amino acids 543-845 of Jak2. The TEL-Jak2 JH2+JH1 construct fuses TEL (1-154) to amino acids 543-1129 of Jak2. TEL-KI-Jak2 JH1 fuses TEL (1-154) to a kinase-inactive form of Jak2 (amino acids 846-1129). All constructs were epitope tagged at the amino terminus with HA₃His₆ (HA). For additional details, please refer to Materials and Methods.