November 4, 2021
Aman Husbands to present Division of Biology Seminar
Submitted by Division of Biology
Aman Husbands, assistant professor of molecular genetics at The Ohio State University, will present "Regulation of HD-ZIPIII Transcription Factors by their Deeply-Conserved START Domain" as part of the Division of Biology Seminar Series at 3:30 p.m. Monday, Nov. 8, in 221 Ackert Hall.
Development results from tightly controlled gene expression driven by the activity of transcription factors, or TFs. As such, TF activity is highly regulated, integrating inputs across multiple regulatory levels to impact developmental outcomes. In plants, this is exemplified by CLASS III HOMEODOMAIN-LEUCINE ZIPPER, or HD-ZIPIII, proteins, a >700 million-year-old family that arose before the common ancestor of Chlorokybus algae and land plants. HD-ZIPIII TFs were then repeatedly co-opted to regulate pivotal developmental innovations, including stem cell niches, lateral organs and vasculature. HD-ZIPIII activity is regulated by multiple mechanisms, including the miRNA mir166 and the LITTLE ZIPPER, ZPR, family of microProteins. HD-ZIPIII proteins also contain a START domain. Initially identified in animals, START domains adopt an α/β helix-grip fold, creating a hydrophobic pocket that accommodates lipophilic ligands ranging from long-chain fatty acids to sterols to isoprenoids. Remarkably, the impact of the HD-ZIPIII START domain remains unknown, despite their essential roles in development and molecular identification over 20 years ago. Using PHABULOSA, or PHB, as a representative HD-ZIPIII protein, we demonstrate that the START domain renders HD-ZIPIII dimers competent to bind DNA, while increasing both their frequency and transcriptional potency. The developmental and evolutionary implications of these findings will be discussed. Husbands will also briefly discuss efforts to use flat leaf production as a model to identify determinants and relationships that lend robustness to the complex process of development.
If you would like to visit with Husbands, please contact Kathrin Schrick at kschrick@k-state.edu.