Biology subjects

Flynn, S. M.

Publications and source records attributed to Flynn, S. M..

3 recordsLinked to original sources

bioRxiv2021

Interactome analysis of C. elegans synapses by TurboID-based proximity labeling

Proximity labelling provides a powerful in vivo tool to characterize the proteome of sub-cellular structures and the interactome of specific proteins. Using the highly active biotin ligase TurboID, we optimize a proximity labelling protocol for C. elegans. We use this protocol to characterise the proteomes of the worms gut, muscle, skin, and nervous system. We express TurboID exclusively in the pair of AFD neurons and show we can identify known and previously unknown proteins expressed selectively in AFD. We knock TurboID into the endogenous elks-1 gene, which encodes a presynaptic active zone protein. We identify many known ELKS-1 interacting proteins as well as previously uncharacterised synaptic proteins. Versatile vectors, and the inherent advantage of C. elegans for biochemistry, make proximity labelling a valuable addition to the nematodes armory. TeaserWe optimize a TurboID proximity labeling protocol for C. elegans and use it to characterize tissue and synaptic proteomes

biochemistry↗

bioRxiv2020

Transcriptional Control Of Calmodulin By CAMTA Regulates Neural Excitability

Calmodulin (CaM) is the major calcium ion (Ca2+) sensor in many biological processes, regulating for example the CaM kinases, calcineurin, and many ion channels. CaM levels are limiting in cells compared to its myriad targets, but how CaM levels are controlled is poorly understood. We find that CaM abundance in the C. elegans and Drosophila nervous systems is controlled by the CaM-binding transcription activator, CAMTA. C. elegans CAMTA (CAMT-1), like its fly and mammalian orthologues, is expressed widely in the nervous system. camt-1 mutants display pleiotropic behavioural defects and altered Ca2+ signaling in neurons. Using FACS-RNA Seq we profile multiple neural types in camt-1 mutants and find all exhibit reduced CaM mRNA compared to controls. Supplementing CaM levels using a transgene rescues camt-1 mutant phenotypes. Chromatin immunoprecipitation sequencing (ChIP-Seq) data show that CAMT-1 binds several sites in the calmodulin promoter. CRISPR-mediated deletion of these sites shows they redundantly regulate calmodulin expression. We also find that CaM can feed back to inhibit its own expression by a mechanism that depends on CaM binding sites on CAMT-1. This work uncovers a mechanism that can both activate and inhibit CaM expression in the nervous system, and controls Ca2+ homeostasis, neuronal excitability and behavior.

neuroscience↗

bioRxiv2019

MALT1 mediates IL-17 Neural Signaling to regulate C. elegans behavior, immunity and longevity

Besides well-known immune roles, the evolutionarily ancient cytokine interleukin-17 (IL-17) modulates neural circuit function. We investigate how IL-17 signals in neurons, and the extent to which this signaling can alter organismal phenotypes. We combine immunoprecipitation and mass spectrometry to biochemically characterize endogenous signaling complexes that function downstream of IL-17 receptors in C. elegans (Ce) neurons. We identify the Ce ortholog of MALT1 as a critical output of the pathway. MALT1 was not previously implicated in IL-17 signaling or in nervous system function. MALT1 forms a complex with homologs of Act1 and IRAK and functions both as a scaffold for I{kappa}B recruitment, and as a protease. MALT1 is expressed broadly in the Ce nervous system, and neuronal IL-17-MALT1 signaling regulates many phenotypes, including escape behavior, associative learning, immunity and longevity. Our data suggest MALT1 has an ancient role modulating neural function downstream of IL-17 to remodel physiological and behavioral state.

neuroscience↗