The world's first wiki where authorship really matters (Nature Genetics, 2008). Due credit and reputation for authors. Imagine a global collaborative knowledge base for original thoughts. Search thousands of articles and collaborate with scientists around the globe.

wikigene or wiki gene protein drug chemical gene disease author authorship tracking collaborative publishing evolutionary knowledge reputation system wiki2.0 global collaboration genes proteins drugs chemicals diseases compound
Hoffmann, R. A wiki for the life sciences where authorship matters. Nature Genetics (2008)



Gene Review

TEM1  -  Ras family GTPase TEM1

Saccharomyces cerevisiae S288c

Synonyms: Protein TEM1, YML064C
Welcome! If you are familiar with the subject of this article, you can contribute to this open access knowledge base by deleting incorrect information, restructuring or completely rewriting any text. Read more.

High impact information on TEM1

  • In S. cerevisiae cells undergoing anaphase, a ras-related GTPase, Tem1, is located on the spindle pole body that enters the daughter cell and activates a signal transduction pathway, MEN, to allow mitotic exit [1].
  • During mitosis, a ras-related GTPase (Tem1) binds GTP and activates a signal transduction pathway to allow mitotic exit [2].
  • We also find that the presence of Tem1 and Lte1 in the bud is required for mitotic exit [3].
  • We find that the GTP binding protein Tem1, a regulator of mitotic exit, is present on the spindle pole body that migrates into the bud during S phase and mitosis [3].
  • Thus, Tem1 and Lte1 are present in the same cellular compartment (the bud) only after the nucleus enters the bud during nuclear division [3].

Biological context of TEM1

  • The yeast TEM1 gene, which encodes a GTP-binding protein, is involved in termination of M phase [4].
  • We have identified TEM1 as a gene that, when present on a multicopy plasmid, suppresses the cold-sensitive phenotype of lte1 [4].
  • The defect of TEM1 was lethal, and the tem1-defective cells were arrested at telophase with high H1-kinase activity under restrictive conditions, indicating that TEM1 is required to exit from M phase [4].
  • Unlike TEM1, LTE1 is not restricted to mitosis but is expressed throughout the cell cycle [5].
  • These data support the view that the spindle assembly checkpoint encompasses regulation of distinct mitotic steps, including a MAD2-directed block to anaphase initiation and a BUB2-directed block to TEM1-dependent exit [6].

Associations of TEM1 with chemical compounds

  • Inappropriate sister chromatid separation in nocodazole-treated bub2 cells is prevented when mitotic exit is blocked using a conditional tem1(c) mutant, indicating that the preanaphase failure in bub2 cells is a consequence of events downstream of TEM1 in the mitotic exit pathway [6].
  • By random mutagenesis of Bfa1-D8(391-574) with hydroxylamine, we isolated a point mutant of D8, D8(E438K), which interacts with both Tem1p and Bub2p but cannot respond to checkpoint signals [7].

Physical interactions of TEM1

  • These findings suggested the hypothesis that movement of the spindle pole through the neck allows Tem1p to interact with Lte1p, promoting GTP loading of Tem1p and mitotic exit [8].
  • Thus, in nud1-2 cells the failure of Tem1p to interact with Cdc15p at the SPB probably prevents mitotic exit [9].

Regulatory relationships of TEM1


Other interactions of TEM1

  • Both events depend on the mitotic exit pathway components TEM1 and CDC15 [13].
  • In the spindle checkpoint pathway, this is accomplished through Bfa1/Bub2, a heteromeric GTPase-activating protein (GAP) that inhibits Clb degradation by keeping the G protein Tem1 inactive [3-5] [14].
  • Tem1 is required for Cdc14 activation [14].
  • By sequence analysis, Tem1p has highest similarity to Vps21p (yeast homolog of mammalian Rab5) [5].
  • In addition, inhibition of PAK kinases by Cla4t prevents mitotic exit also by a Swe1-independent mechanism impinging directly on the MEN activator Tem1 [15].

Analytical, diagnostic and therapeutic context of TEM1

  • Sequence analysis of TEM1 and GTP-binding analysis of the gene product revealed that TEM1 encodes a novel low-molecular-weight GTP-binding protein [4].


  1. Exit from exit: resetting the cell cycle through Amn1 inhibition of G protein signaling. Wang, Y., Shirogane, T., Liu, D., Harper, J.W., Elledge, S.J. Cell (2003) [Pubmed]
  2. Regulation of the Bub2/Bfa1 GAP complex by Cdc5 and cell cycle checkpoints. Hu, F., Wang, Y., Liu, D., Li, Y., Qin, J., Elledge, S.J. Cell (2001) [Pubmed]
  3. A mechanism for coupling exit from mitosis to partitioning of the nucleus. Bardin, A.J., Visintin, R., Amon, A. Cell (2000) [Pubmed]
  4. The yeast TEM1 gene, which encodes a GTP-binding protein, is involved in termination of M phase. Shirayama, M., Matsui, Y., Toh-E, A. Mol. Cell. Biol. (1994) [Pubmed]
  5. A role for Lte1p (a low temperature essential protein involved in mitosis) in proprotein processing in the yeast secretory pathway. Zhao, X., Chang, A.Y., Toh-E, A., Arvan, P. J. Biol. Chem. (2007) [Pubmed]
  6. Saccharomyces cerevisiae BUB2 prevents mitotic exit in response to both spindle and kinetochore damage. Krishnan, R., Pangilinan, F., Lee, C., Spencer, F. Genetics (2000) [Pubmed]
  7. The C-terminus of Bfa1p in budding yeast is essential to induce mitotic arrest in response to diverse checkpoint-activating signals. Kim, J., Jeong, J., Song, K. Genes Cells (2004) [Pubmed]
  8. The surveillance mechanism of the spindle position checkpoint in yeast. Adames, N.R., Oberle, J.R., Cooper, J.A. J. Cell Biol. (2001) [Pubmed]
  9. Nud1p links astral microtubule organization and the control of exit from mitosis. Gruneberg, U., Campbell, K., Simpson, C., Grindlay, J., Schiebel, E. EMBO J. (2000) [Pubmed]
  10. Bfa1 can regulate Tem1 function independently of Bub2 in the mitotic exit network of Saccharomyces cerevisiae. Ro, H.S., Song, S., Lee, K.S. Proc. Natl. Acad. Sci. U.S.A. (2002) [Pubmed]
  11. Spatial regulation of the guanine nucleotide exchange factor Lte1 in Saccharomyces cerevisiae. Jensen, S., Geymonat, M., Johnson, A.L., Segal, M., Johnston, L.H. J. Cell. Sci. (2002) [Pubmed]
  12. The Tem1 small GTPase controls actomyosin and septin dynamics during cytokinesis. Lippincott, J., Shannon, K.B., Shou, W., Deshaies, R.J., Li, R. J. Cell. Sci. (2001) [Pubmed]
  13. Regulation of the mitotic exit protein kinases Cdc15 and Dbf2. Visintin, R., Amon, A. Mol. Biol. Cell (2001) [Pubmed]
  14. The Bfa1/Bub2 GAP complex comprises a universal checkpoint required to prevent mitotic exit. Wang, Y., Hu, F., Elledge, S.J. Curr. Biol. (2000) [Pubmed]
  15. Budding yeast PAK kinases regulate mitotic exit by two different mechanisms. Chiroli, E., Fraschini, R., Beretta, A., Tonelli, M., Lucchini, G., Piatti, S. J. Cell Biol. (2003) [Pubmed]
WikiGenes - Universities