PXD056261

PXD056261 is an original dataset announced via ProteomeXchange.

Title	Mechanisms of amphibian arrestin 1 self-association and dynamic distribution in retinal photoreceptors
Description	Visual arrestin 1 (Arr1) is an essential protein for termination of the light response in photoreceptors. While mammalian Arr1s form dimers and tetramers at physiological concentrations in vitro, oligomerization in other vertebrates has not been studied. We examined self-association of African clawed frog, Xenopus laevis (xArr1), and salamander, Ambystoma tigrinum (salArr1) Arr1. Sedimentation velocity analytical ultracentrifugation (AUC) showed that xArr1 and salArr1 oligomerization is limited to dimers. The KD for dimer formation was 53 µM for xArr1 and 44 µM for salArr1, similar to the 69 M KD for bovine Arr1 (bArr1) dimers. Mutations of orthologous amino acids important for mammalian Arr1 oligomerization had no impact on xArr1 dimerization. Crystal structure analysis showed that the fold of xArr1 closely resembles that of bArr1. Two xArr1 crystal structures in different space groups revealed two potential xArr1 dimer forms: a dimer with symmetrical packing interfaces from the C-domains of two monomers (CC dimer), similar to that previously predicted from the bArr1 solution structure and a previously observed dimer stabilized by contacts from the N-domain from one monomer and the C-domain from the opposite monomer (CN dimer), and revealed an interdomain rotation in xArr1 dimers that may explain the absence of tetramers. Mutagenesis of residues predicted to interact in either of the two dimer forms yielded modest reduction in dimer affinity, suggesting that the dimer interfaces compete or are not unique. SAXS shows the solution dimer differs from all previous dimers, supporting this conclusion. Finally, a computational model evaluating xArr1 binding to compartment-specific partners and partitioning based on heterogeneity of available cytoplasmic spaces shows that the majority of Arr1 distribution in dark adapted photoreceptors is explained by the excluded volume effect.
HostingRepository	jPOST
AnnounceDate	2025-09-26
AnnouncementXML	Submission_2025-09-25_08:00:04.724.xml
DigitalObjectIdentifier
ReviewLevel	Non peer-reviewed dataset
DatasetOrigin	Original dataset
RepositorySupport	Unsupported dataset by repository
PrimarySubmitter	Bruce Knutson
SpeciesList	scientific name: Xenopus; NCBI TaxID: 8353;
ModificationList	S-carboxamidomethyl-L-cysteine; L-methionine sulfoxide
Instrument	Orbitrap Fusion Lumos

Revision	Datetime	Status	ChangeLog Entry
0	2024-09-25 14:55:00	ID requested
⏵ 1	2025-09-25 08:00:05	announced

Dataset with its publication pending

submitter keyword: arr1, protein painting

Bruce Knutson
lab head
Bruce Knutson
contact affiliation	SUNY Upstate Medical University
dataset submitter

jPOST dataset URI

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