Biology subjects

Yang, S. Z.

Publications and source records attributed to Yang, S. Z..

3 recordsLinked to original sources

bioRxiv2023

Handling difficult cryo-ET samples: A study with primary neurons from Drosophila melanogaster

Cellular neurobiology has benefited from recent advances in the field of cryo-electron tomography (cryo-ET). Numerous structural and ultrastructural insights have been obtained from plunge-frozen primary neurons cultured on electron microscopy grids. With most primary neurons been derived from rodent sources, we sought to expand the breadth of sample availability by using primary neurons derived from 3rd instar Drosophila melanogaster larval brains. Ultrastructural abnormalities were encountered while establishing this model system for cryo-ET, which were exemplified by excessive membrane blebbing and cellular fragmentation. To optimize neuronal samples, we integrated substrate selection, micropatterning, montage data collection, and chemical fixation. Efforts to address difficulties in establishing Drosophila neurons for future cryo-ET studies in cellular neurobiology also provided insights that future practitioners can use when attempting to establish other cell-based model systems.

biophysics↗

bioRxiv2021

Acetylated α-tubulin residue K394 regulates microtubule stability to shape the growth of axon terminals

Microtubules are essential to neuron shape and function. Therefore, the stability of the microtubule cytoskeleton must be carefully regulated. Acetylation of tubulin has the potential to directly tune microtubule stability, and proteomic studies have identified several acetylation sites in -tubulin. This includes the highly conserved residue lysine 394 (K394), which is located at the {beta}-tubulin dimer interface. Using a fly model, we show that -tubulin K394 is acetylated in the nervous system and is an essential residue. We found that an acetylation-blocking mutation in endogenous -tubulin, K394R, perturbs the synaptic morphogenesis of motoneurons by reducing microtubule stability. Intriguingly, the K394R mutation has opposite effects on the growth of two functionally and morphologically distinct motoneurons, revealing neuron-type-specific responses when microtubule stability is altered. Eliminating the deacetylase HDAC6 increases K394 acetylation, and the over-expression of HDAC6 reduces microtubule stability similar to the K394 mutant. Thus, our findings implicate -tubulin K394 and its acetylation in the regulation of microtubule stability and suggest that HDAC6 regulates K394 acetylation during synaptic morphogenesis.

cell biology↗

bioRxiv2019

Golgi outposts locally regulate microtubule orientation in neurons but are not required for the overall polarity of the dendritic cytoskeleton

Microtubule-organizing centers (MTOCs) often play a central role in organizing the cellular microtubule networks that underlie cell function. In neurons, microtubules in axons and dendrites have distinct polarities. Dendrite-specific Golgi outposts, in particular multi-compartment outposts, have emerged as regulators of acentrosomal microtubule growth, raising the question of whether outposts contribute to establishing the overall polarity of the dendritic microtubule cytoskeleton. The cis-Golgi matrix protein GM130 has roles in both the MTOC activity of Golgi and in connecting Golgi compartments to form multi-compartment units. Using a combination of genetic approaches and live imaging in a Drosophila model, we found that GM130 is not essential for the overall polarity of the dendritic microtubule cytoskeleton. However, the mislocalization of multi-compartment Golgi outposts to axons disrupts the uniform orientation of axonal microtubules. This suggests that outposts have the capacity to influence microtubule polarity and, as our data indicate, likely do so independently of microtubule nucleation mediated by the {gamma}-tubulin ring complex ({gamma}-TuRC). Altogether, our results are consistent with the model that multi-compartment Golgi outposts may locally influence microtubule polarity, but that outposts are not necessary for the overall polarity of the dendritic microtubule cytoskeleton.

cell biology↗