Xenbase Image ID: 87010

Figure 4: Irx5 interacts with zinc-finger transcription factors Gata3 and Trps1 to regulate craniofacial morphogenesis. a–c) Irx5 (a), Trps1 (b) and Gata3 (c) were expressed in nested regions of developing X. laevis head at stage (st.) 33. (d) Irx5, Trps1 and Gata3 transcripts (pink) colocalized to ventral region of four branchial arches (1–4), otic vesicle (ov) and frontonasal process (fp). Irx5 and Trps1 (yellow) were coexpressed in most anterior three branchial arches (1–3). Irx5 and Gata3 mRNA (green) were seen in developing lens (le). (e) Irx5 coimmunoprecipitated with wild-type Trps1 (lane 2), and to a lesser extent with the variant18 (lane 4). IP, immunoprecipitation; IB, immunoblot. Irx5 N166K protein was pulled down by wild-type Trps1 (lane 3). (f) Gata3 coimmunoprecipitated with wild-type Irx5 (lane 2), and to a lesser extent with mutant Irx5 N166K (lane 3). (g,h) Trps1 promoted Irx5-dependent transactivation of Kcnd2 promoter luciferase construct. Conversely, Gata3 inhibited Irx5-dependent transactivation of Kcnd2 reporter. Data are mean ± s.d. *P < 0.05; **P < 0.005; one-tailed Student's t test). (i) Increasing amounts of Trps1 dose-dependently enhanced binding of Gata3 to Irx5 (lanes 2–5). (j) Increasing amounts of Trps1 potentiated inhibitory role of Gata3 on Irx5-mediated transactivation of Kcnd2 reporter. Data are mean ± s.d. *P < 0.05; **P < 0.005 (one-tailed Student's t test). (k) Schematic of IRX5 and IRX3 proteins, in complex with comodulators TRPS1 and GATA3, tuning transcription of target genes such as SDF1 for chemoattraction of migratory populations of NCCs and germ cells. Image published in: Bonnard C et al. (2012) Copyright © 2012. Image reproduced with permission of the Publisher, Macmillan Publishers Ltd. Larger Image Printer Friendly View

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