Biology subjects

Maurel-Zaffran, C.

Publications and source records attributed to Maurel-Zaffran, C..

2 recordsLinked to original sources

bioRxiv2026

Intrinsically disordered regions influence protein motif usage in Drosophila Ubx and AbdA Hox proteins

Hox proteins are evolutionary conserved transcription factors guiding morphogenesis in all bilaterian animals. Conservation mainly concerns the homeodomain (HD), a helix-turn-helix DNA binding motif and flanking sequences close by. Besides, sequences are poorly conserved and disordered. Here we investigate how poorly conserved Intrinsically Disordered Regions (IDRs) influence Hox protein activity, focusing on a closely related Drosophila Hox pair and using a wide range of in vivo function. Studying Drosophila Ultrabithorax (Ubx) and AbdominalA (AbdA) proteins, we find that conserved protein motifs close to the HD are differently used in Ubx and AbdA. Coarse-grained molecular dynamics simulations identify a large set of intra-molecular interactions, notably involving poorly conserved disordered regions upstream and downstream the HD. Swapping these regions in Ubx and AbdA alters protein functions and switches motif dependency in some biological situations. This suggests that IDRs, predicted to mediate large and dynamic sets of intramolecular interactions, influence protein motif usage in a context dependent manner.

developmental biology↗

bioRxiv2020

Hox-dependent coordination of cardiac progenitor cell patterning and differentiation

Perturbation of addition of second heart field (SHF) cardiac progenitor cells to the poles of the heart tube results in congenital heart defects (CHD). The transcriptional programs and upstream regulatory events operating in different subpopulations of the SHF remain unclear. Here, we profile the transcriptome and chromatin accessibility of anterior and posterior SHF sub-populations at genome-wide levels and demonstrate that Hoxb1 negatively regulates differentiation in the posterior SHF. Spatial mis-expression of Hoxb1 in the anterior SHF results in hypoplastic right ventricle. Activation of Hoxb1 in embryonic stem cells arrests cardiac differentiation, whereas Hoxb1-deficient embryos display premature cardiac differentiation. Moreover, ectopic differentiation in the posterior SHF of embryos lacking both Hoxb1 and its paralog Hoxa1 results in atrioventricular septal defects. Our results show that Hoxb1 plays a key role in patterning cardiac progenitor cells that contribute to both cardiac poles and provide new insights into the pathogenesis of CHD.

developmental biology↗