18 research outputs found
Gender differences in suicide attempters: a retrospective study of precipitating factors for suicide attempts at a critical emergency unit in Japan
Kinetics and Mechanism of Dimethyl Ether Oxidation to Formaldehyde on Supported Molybdenum Oxide Domains
Controlling plasma composition during carbon film deposition in microwave discharges by means of optical-emission spectroscopy
Transmural microcirculatory blood flow distribution in right and left ventricular free walls of rabbits
Effect of Angiotensin Blockade on the Association Between Albuminuria and Peripheral Arterial Disease in Elderly Taiwanese Patients With Type 2 Diabetes Mellitus
Suicide and suicide attempts in adults: exploring suicide risk 24 months after a psychiatric emergency room visit
Global Regulation of the Interphase Microtubule System by Abundantly Expressed Op18/Stathmin
Op18/stathmin (Op18), a conserved microtubule-depolymerizing and tubulin heterodimer-binding protein, is a major interphase regulator of tubulin monomer–polymer partitioning in diverse cell types in which Op18 is abundant. Here, we addressed the question of whether the microtubule regulatory function of Op18 includes regulation of tubulin heterodimer synthesis. We used two human cell model systems, K562 and Jurkat, combined with strategies for regulatable overexpression or depletion of Op18. Although Op18 depletion caused extensive overpolymerization and increased microtubule content in both cell types, we did not detect any alteration in polymer stability. Interestingly, however, we found that Op18 mediates positive regulation of tubulin heterodimer content in Jurkat cells, which was not observed in K562 cells. By analysis of cells treated with microtubule-poisoning drugs, we found that Jurkat cells regulate tubulin mRNA levels by a posttranscriptional mechanism similarly to normal primary cells, whereas this mechanism is nonfunctional in K562 cells. We present evidence that Op18 mediates posttranscriptional regulation of tubulin mRNA in Jurkat cells through the same basic autoregulatory mechanism as microtubule-poisoning drugs. This, combined with potent regulation of tubulin monomer–polymer partitioning, enables Op18 to exert global regulation of the microtubule system