Biology subjects

Chang, C.-Y.

Publications and source records attributed to Chang, C.-Y..

3 recordsLinked to original sources

bioRxiv2019

Dual linker UNC-10/SYD-2 is sufficient to bind kinesin-3 UNC-104 to RAB-3 containing synaptic vesicles in the absence of the motor’s PH domain

Kinesin-3 KIF1A (UNC-104 in C. elegans) is the major axonal transporter of synaptic vesicles and mutations in this molecular motor are linked to KIF1A-associated neurological disorders (KAND) including Charcot-Marie-Tooth disease, amyotrophic lateral sclerosis and hereditary spastic paraplegia. UNC-104 binds via its PH (pleckstrin homology) domain to the lipid bilayers of membranous vesicles which is considered a weak interaction. RT-PCR and Western blot experiments reveal genetic relations between SYD-2, UNC-10 and RAB-3. Co-immunoprecipitation assays reveal functional relations and bimolecular fluorescence complementation (BiFC) assays expose in situ interactions between these proteins. Though both SNB-1 and RAB-3 are actively transported by UNC-104, the movement of RAB-3 is generally enhanced and largely depending on the presence of SYD-2/UNC-10. Deletion of UNC-104s PH domain did not affect UNC-104/RAB-3 colocalization but did affect UNC-104/SNB-1 colocalization. Similarly, motility of RAB-3-labeled vesicles is unaltered in nematodes carrying a point mutation in the PH domain while movement of SNB-1 is significantly reduced in anterograde directions. These findings suggest a dual UNC-10/SYD-2 linker acting as a sufficient buttress to connect the motor to RAB-3-containing vesicles to enhance their transport. This additional linker will also strengthen the rather weak motor-lipid interaction. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=70 SRC="FIGDIR/small/723247v4_ufig1.gif" ALT="Figure 1"> View larger version (18K): org.highwire.dtl.DTLVardef@5e41c0org.highwire.dtl.DTLVardef@2ed9c8org.highwire.dtl.DTLVardef@1dbdb9dorg.highwire.dtl.DTLVardef@12f30c2_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗

bioRxiv2019

Sonogenetic modulation of cellular activities using an engineered auditory-sensing protein

Biomolecules that respond to different external stimuli enable the remote control of genetically modified cells. Chemogenetics and optogenetics, two tools that can control cellular activities via synthetic chemicals or photons, respectively, have been widely used to elucidate underlying physiological processes. These methods are, however, very invasive, have poor penetrability, or low spatiotemporal precision, attributes that hinder their use in therapeutic applications. We report herein a sonogenetic approach that can manipulate target cell activities by focused ultrasound stimulation. This system requires an ultrasound-responsive protein derived from an engineered auditory-sensing protein prestin. Heterogeneous expression of mouse prestin containing two parallel amino acid substitutions, N7T and N308S, that frequently exist in prestins from echolocating species endowed transfected mammalian cells with the ability to sense ultrasound. An ultrasound pulse of low frequency and low pressure efficiently evoked cellular calcium responses after transfecting with prestin(N7T, N308S). Moreover, pulsed ultrasound can also non-invasively stimulate target neurons expressing prestin(N7T, N308S) in deep regions of mice brains. Our study delineates how an engineered auditory-sensing protein can cause mammalian cells to sense ultrasound stimulation. Moreover, owing to the great penetration of low-frequency ultrasound ([~]400 mm in depth), our sonogenetic tools will serve as new strategies for non-invasive therapy in deep tissues of large animals like primates.

bioengineering↗

bioRxiv2019

Recapitulation and reversal of schizophrenia-related phenotypes in Setd1a-deficient mice

SETD1A, a histone methyltransferase, is a key schizophrenia susceptibility gene. Mutant mice carrying a heterozygous loss-of-function mutation of the orthologous gene exhibit alterations in axonal branching and cortical synaptic dynamics, accompanied by specific deficits in working memory that recapitulates SCZ-related alterations. We show that Setd1a targets mostly enhancers and reveal a striking overlap between Setd1a and Mef2 chromatin targets. Setd1a targets are highly expressed in pyramidal neurons and enriched for genes with postnatally-biased expression involved in synaptic structure and function. Notably, evolutionary conserved Setd1a binding sites and target genes are strongly associated with neuropsychiatric genetic risk burden. Reinstating Setd1a expression in adulthood rescues working memory deficits. We identify LSD1 as a major demethylase counteracting the effects of Setd1a methyl transferase activity and show that LSD1 antagonism in adult Setd1a-deficient mice results in a full rescue of the behavioral abnormalities and axonal branching deficits. Our findings advance our understanding of how SETD1A mutations predispose to SCZ and point to therapeutic interventions.

neuroscience↗