Synthesis and Effect of Conformationally Locked Carbocyclic Guanine Nucleotides on Dynamin.

TitleSynthesis and Effect of Conformationally Locked Carbocyclic Guanine Nucleotides on Dynamin.
Publication TypeJournal Article
Year of Publication2022
AuthorsToti, KS, Jimah, JR, Salmaso, V, Hinshaw, JE, Jacobson, KA
JournalBiomolecules
Volume12
Issue4
Date Published2022 04 16
ISSN2218-273X
KeywordsCryoelectron Microscopy, Dynamins, Guanine Nucleotides, Guanosine Triphosphate, Lipids, Ribose
Abstract

<p>Guanine nucleotides can flip between a North and South conformation in the ribose moiety. To test the enzymatic activity of GTPases bound to nucleotides in the two conformations, we generated methanocarba guanine nucleotides in the North or South envelope conformations, i.e., (N)-GTP and (S)-GTP, respectively. With dynamin as a model system, we examined the effects of (N)-GTP and (S)-GTP on dynamin-mediated membrane constriction, an activity essential for endocytosis. Dynamin membrane constriction and fission activity are dependent on GTP binding and hydrolysis, but the effect of the conformational state of the GTP nucleotide on dynamin activity is not known. After reconstituting dynamin-mediated lipid tubulation and membrane constriction in vitro, we observed via cryo-electron microscopy (cryo-EM) that (N)-GTP, but not (S)-GTP, enables the constriction of dynamin-decorated lipid tubules. These findings suggest that the activity of dynamin is dependent on the conformational state of the GTP nucleotide. However, a survey of nucleotide ribose conformations associated with dynamin structures in nature shows almost exclusively the (S)-conformation. The explanation for this mismatch of (N) vs. (S) required for GTP analogues in a dynamin-mediated process will be addressed in future studies.</p>

DOI10.3390/biom12040584
Alternate JournalBiomolecules
PubMed ID35454173
PubMed Central IDPMC9031165
Grant ListK99 GM140220 / GM / NIGMS NIH HHS / United States
R00 GM140220 / GM / NIGMS NIH HHS / United States
ZIADK031116 / DK / NIDDK NIH HHS / United States
ZIADK60107 / DK / NIDDK NIH HHS / United States