PubMed Health⌕ Search

PubMed · 14560948

TOR: the first 10 years.

Abstract

TOR was discovered and christened 10 years ago. On the occasion of this anniversary, we revisit the discovery of TOR and chronicle subsequent breakthroughs in S. cerevisiae that contributed to an understanding of TOR function in yeast and higher eukaryotes. In particular, we discuss findings that led to the realization that the function of TOR is to control cell growth in response to nutrients.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

A Lorberg, M N Hall. 2004. TOR: the first 10 years.. https://doi.org/10.1007/978-3-642-18930-2_1

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

[Effect of 4 degrees C pretreatment on the membrane current and cell polarity in human neutrophils].

To investigate the role of ion channels in the coupling responses of neutrophils to extracellular stimulus, it is necessary to study the membrane ion channel activities using patch-clamp technique. However, little has been known about the ion channel activities in neutrophils due to the difficulties in forming giga-seal with pipettes because of small diameter of neutrophils and the easily developed polarization. Some studies indicated that favorable results could be achieved through pretreatment at low temperature before electrophysiological recordings. But it remains unclear whether the pretreatment affects the membrane current and why the seal rate increases after low temperature pretreatment. The purpose of this study was to investigate the effects of 4 degrees C pretreatment on the membrane current and cell polarity in human neutrophils. In the experiments, human neutrophils were isolated from fresh peripheral blood of healthy volunteers and divided into two groups (room temperature group and 4 degrees C pretreatment group). Voltage-dependent K(+) (Kv) currents were recorded in whole-cell voltage-clamp mode and large-conductance Ca(2+)-activated K(+) (BK(Ca)) currents were recorded using inside-out patches. The results showed that 4 degrees C pretreatment significantly inhibited cell polarity (P<0.05), and it took more time for neutrophils to form a polarity-cycle [(534+/-32) s, n=20] compared with those at room temperature [(257+/-24) s, n=20]. Meanwhile, seal rate significantly increased in 4 degrees C pretreatment group (64%) compared with that in the room temperature group (27.5%). The seal rate and cell polarity rate during 0 approximately 1 min after 4 degrees C pretreatment were significantly different from those at room temperature, while no significant difference was found during 9 approximately 10 min between the two groups. Our results suggest that 4 degrees C pretreatment can inhibit cell polarity and increase seal rate, but has no effects on membrane currents. It is also suggested that 0 approximately 1 min after 4 degrees C pretreatment is a more suitable time for electrophysiological recording in neutrophils.

Cell Polarity↗

Role of Rho GTPases and Rho-GEFs in the regulation of cell shape and integrity in fission yeast.

The Rho family of GTPases are highly conserved molecular switches that control some of the most fundamental processes of cell biology, including morphogenesis, vesicular transport, cell division and motility. Guanine nucleotide-exchange factors (GEFs) are directly responsible for the activation of Rho-family GTPases in response to extracellular stimuli. In fission yeast, there are seven Dbl-related GEFs and they activate six Rho-type GTPases within a particular spatio-temporal context. The failure to do so might have consequences reflected in aberrant phenotypes and in some cases lead to cell death. In this review, we briefly summarize the role of Rho GTPases and Rho-GEFs in the establishment and maintenance of cell polarity and cell integrity in Schizosaccharomyces pombe.

Cell Polarity↗

Kinesin-5 motors are required for organization of spindle microtubules in Silvetia compressa zygotes.

BACKGROUND: Monastrol, a chemical inhibitor specific to the Kinesin-5 family of motor proteins, was used to examine the functional roles of Kinesin-5 proteins during the first, asymmetric cell division cycle in the brown alga Silvetia compressa. RESULTS: Monastrol treatment had no effect on developing zygotes prior to entry into mitosis. After mitosis entry, monastrol treatment led to formation of monasters and cell cycle arrest in a dose dependent fashion. These findings indicate that Kinesin-5 motors maintain spindle bipolarity, and are consistent with reports in animal cells. At low drug concentrations that permitted cell division, spindle position was highly displaced from normal, resulting in abnormal division planes. Strikingly, application of monastrol also led to formation of numerous cytasters throughout the cytoplasm and multipolar spindles, uncovering a novel effect of monastrol treatment not observed in animal cells. CONCLUSION: We postulate that monastrol treatment causes spindle poles to break apart forming cytasters, some of which capture chromosomes and become supernumerary spindle poles. Thus, in addition to maintaining spindle bipolarity, Kinesin-5 members in S. compressa likely organize microtubules at spindle poles. To our knowledge, this is the first functional characterization of the Kinesin-5 family in stramenopiles.

Cell Polarity↗