Publications by authors named "Bryce A Brownfield"
Sec7 regulatory domains scaffold autoinhibited and active conformations.
Proc Natl Acad Sci U S A
March 2024
The late stages of Golgi maturation involve a series of sequential trafficking events in which cargo-laden vesicles are produced and targeted to multiple distinct subcellular destinations. Each of these vesicle biogenesis events requires activation of an Arf GTPase by the Sec7/BIG guanine nucleotide exchange factor (GEF). Sec7 localization and activity is regulated by autoinhibition, positive feedback, and interaction with other GTPases.
View Article and Find Full Text PDFArticle Synopsis
- The late stages of Golgi maturation involve producing cargo-laden vesicles that are targeted to various subcellular locations, relying on the activation of Arf GTPases by the Sec7/BIG guanine nucleotide exchange factor (GEF).
- Sec7's localization and activity are controlled by mechanisms like autoinhibition, positive feedback, and interactions with other GTPases, but the full details of this regulation remain unclear.
- The study presents the cryoEM structure of autoinhibited Sec7, revealing its regulatory domains, and explains the transition to an active form on organelle membranes through functional experiments and structural predictions.
RNA degradation is fundamental for cellular homeostasis. The process is carried out by various classes of endolytic and exolytic enzymes that together degrade an RNA polymer to mono-ribonucleotides. Within the exoribonucleases, nano-RNases play a unique role as they act on the smallest breakdown products and hence catalyze the final steps in the process.
View Article and Find Full Text PDF