Tubulin mRNA stability is sensitive to change in microtubule dynamics caused by multiple physiological and toxic cues

Abstract

The localization, mass, and dynamics of microtubules are important in many processes. Cells may actively monitor the state of their microtubules and respond to perturbation, but how this occurs outside mitosis is poorly understood. We used gene-expression analysis in quiescent cells to analyze responses to subtle and strong perturbation of microtubules. Genes encoding α-, β, and γ-tubulins (TUBAs, TUBBs, and TUBGs), but not δ- or ε-tubulins (TUBDs or TUBEs), exhibited the strongest differential expression response to microtubule-stabilizing versus destabilizing drugs. Quantitative PCR of exon versus intron sequences confirmed that these changes were caused by regulation of tubulin mRNA stability and not transcription. Using tubulin mRNA stability as a signature to query the Gene Expression Omnibus (GEO) database, we find that tubulin genes respond to toxins known to damage microtubules. Importantly, we find many other experimental perturbations, including multiple signaling and metabolic inputs that trigger tubulin differential expression, suggesting their novel, to our knowledge, role in the regulation of the microtubule cytoskeleton. Mechanistic follow-up confirms that one important physiological signal, phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K) activity, indeed regulates tubulin mRNA stability via changes in microtubule dynamics. We propose that tubulin gene expression is regulated as part of many coordinated biological responses, with wide implications in physiology and toxicology. Furthermore, we present a new way to discover microtubule regulation using transcriptomics.

Assessment of common housekeeping genes as reference for gene expression studies using RT-qPCR in mouse choroid plexus

“…Another common family of reference gene includes structural genes, such as Actb (encoding actin protein of cytoskeletal structure) and tubulin (encoding microtubules). It is well-known that tubulin genes are essential for the development and function of neurons 60 , however it has been reported that tubulin mRNA can be unstable under physiological changes 61 ; therefore, we decided to not include it in our study. On the other hand, we did include Actb, one of the most popular gene in the literature.…”

DNA Replication Stress and Chromosomal Instability: Dangerous Liaisons

“…Microtubule stability is posttranscriptionally regulated and depends on the stability of its own mRNA to ensure that microtubules can react promptly to diverse insults [150]. This mechanism depends on the availability of tubulin monomers, which negatively regulate mature spliced mRNA [151].…”

Visual Cell Sorting: A High-throughput, Microscope-based Method to Dissect Cellular Heterogeneity

“…Morphologically normal cells upregulated the genes encoding actin and microtubules (e.g. Figure 4E), a well-documented response to microtubule damage and paclitaxel treatment 33 . We also noted that these cells upregulated the chaperone clusterin (CLU) and its co-activator HSPA5, which together decrease paclitaxel-mediated apoptosis by stabilizing mitochondrial membrane potential 34 .…”