New & Noteworthy

New Understanding of ER Membrane Expansion´┐╝

January 28, 2022

How lipid metabolism gets coordinated with membrane growth in response to environment has remained an unexplained phenomenon. A recent paper explains key components in how cells manage this response.

Organelle biogenesis typically requires synthesis of new membrane and thus depends on lipid metabolism. A genetic screen identifies the ER protein Ice2 as a regulator of lipid metabolism and a major factor for ER membrane biogenesis, from Papagiannidis et al.

Papagiannidis et al. demonstrate a key regulatory step via the transmembrane protein Ice2p. Ice2p affects negative regulation of Pah1p (called lipin in metazoa) by inhibiting the Nem1-Spo7 phosphatase complex, which would normally activate Pah1p by dephosphorylation. The study shows that Ice2p also plays a role in transcriptional regulation of lipid synthesis genes, thereby providing a key pivot in the cellular need to make more membrane in response to ER stress.

Categories: Paper of the Week, Uncategorized

Tags: Saccharomyces cerevisiae, Membrane biogenesis, endoplasmic reticulum, lipid regulation

Predicted 3D Structures of Yeast Complexes

January 20, 2022

In an exciting new paper, Humphreys et al. describe the use of deep-learning-based algorithms to predict structures of not only single proteins, but assemblies of proteins. The team used rapid RoseTTAFold combined with the more accurate AlphaFold to build structural models for 106 previously unidentified protein assemblies and 806 complexes that had not been structurally characterized. The complexes have up to five subunits and are involved in numerous critical roles in cell biology.

Examples of predicted complexes from Humphreys et al.

Go look for your own proteins of interest at the ModelArchive and search in the Home page. Also find the link on the resources section of the SGD Interaction and Protein pages.

Categories: Data updates, Uncategorized, Announcements

Tags: yeast protein assembly, Saccharomyces cerevisiae, protein complex