Abstract
The pronounced stimulation of protein synthesis in T lymphocytes in response to mitogens is partly due to increased cell size and hence ribosome number. There is also a large increase in translation rate per ribosome as a result of an increased rate of initiation. In response to mitogen, levels of both eukaryotic initiation factor (eIF)-2 and guanine nucleotide exchange factor, GEF, increase in parallel with ribosomes which is consistent with a general increase in the translational machinery but cannot explain the increase in activity per ribosome. However, as total eIF-2 accumulates, the ratio of phosphorylated eIF-2 alpha (eIF-2(alpha P] to eIF-2 alpha decreases. Further, the levels of eIF-2(alpha P) and GEF in resting T lymphocytes are similar. As eIF-2(alpha P) inhibits GEF by effectively sequestering the exchange factor in an inactive 1:1 complex, the level of GEF available for protein synthesis initiation must be very low in resting cells. Hence, as GEF is synthesized and rises above the level of eIF-2(alpha P), there will be a disproportionate increase in GEF available for initiation compared with the increase in total GEF. This increase in available GEF is probably great enough to support the increase in translation rate per ribosome as well as the increase in ribosome number.
Highlights
The pronounced stimulation of proteinsynthesis in spleen
Translational Inhibitor in Rat T Lymphocyte Lysate Is a Ribonuclease; Calf T Lymphocyte Lysate Lacks a Detectable Translational Inhibitor-A number of reports suggests that the low rates of protein synthesis in resting T lymphocytes may result from the presence of potent translational inhibitors
The present study undertook the investigation of lysates of T lymphocytes from rat spleen and calf spleen for the presence of translational inhibitors, andof the potential role of such inhibitors in T lymphocyte protein synthesis regulation
Summary
The pronounced stimulation of proteinsynthesis in spleen. Our results suggest the presence of this inhibitor in T. We examined and when maintained in culture Their growth is arrested in the potential role of the initiation step involving the Metthe Go stage of the cell cycle, and they do not proliferate tRNA binding factor, eIF-2, a known major control point in despite the presence of adequatenutrients in the culture initiationin eukaryotes, inthe regulation of the protein medium. Consistent with their non-proliferative state, resting synthesis rate inT lymphocytes
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
