ABSTRACT: BACKGROUND: In yeast, glucose-dependent degradation of the Mth1 protein, a corepressor of the glucose transporter gene (HXT) repressor Rgt1, is a crucial event enabling expression of several HXT. This event occurs through a signaling pathway that involves the Rgt2 and Snf3 glucose sensors and yeast casein kinase 1 and 2 (Yck1/2). In this study, we examined whether the glucose sensors directly couple with Yck1/2 to convert glucose binding into an intracellular signal that leads to the degradation of Mth1. RESULTS: High levels of glucose induce degradation of Mth1 through the Rgt2/Snf3 glucose signaling pathway. Fluorescence microscopy analysis indicates that, under glucose-limited conditions, GFP-Mth1 is localized in the nucleus and does not shuttle between the nucleus and cytoplasm. If glucose-induced degradation is prevented due to disruption of the Rgt2/Snf3 pathway, GFP-Mth1 accumulates in the nucleus. When engineered to be localized to the cytoplasm, GFP-Mth1 is degraded regardless of the presence of glucose or the glucose sensors. In addition, removal of Grr1 from the nucleus prevents degradation of GFP-Mth1. These results suggest that glucose-induced, glucose sensor-dependent Mth1 degradation occurs in the nucleus. We also show that, like Yck2, Yck1 is localized to the plasma membrane via C-terminal palmitoylation mediated by the palmitoyl transferase Akr1. However, glucose-dependent degradation of Mth1 is not impaired in the absence of Akr1, suggesting that a direct interaction between the glucose sensors and Yck1/2 is not required for Mth1 degradation. CONCLUSION: Glucose-induced, glucose sensor-regulated degradation of Mth1 occurs in the nucleus and does not require direct interaction of the glucose sensors with Yck1/2.
%0 Journal Article
%1 Pasula2010Role
%A Pasula, Satish
%A Chakraborty, Samujjwal
%A Choi, Jae H.
%A Kim, Jeong-Ho H.
%D 2010
%J BMC cell biology
%K glucose-signalling yeast
%N 1
%P 17+
%R 10.1186/1471-2121-11-17
%T Role of casein kinase 1 in the glucose sensor-mediated signaling pathway in yeast.
%U http://dx.doi.org/10.1186/1471-2121-11-17
%V 11
%X ABSTRACT: BACKGROUND: In yeast, glucose-dependent degradation of the Mth1 protein, a corepressor of the glucose transporter gene (HXT) repressor Rgt1, is a crucial event enabling expression of several HXT. This event occurs through a signaling pathway that involves the Rgt2 and Snf3 glucose sensors and yeast casein kinase 1 and 2 (Yck1/2). In this study, we examined whether the glucose sensors directly couple with Yck1/2 to convert glucose binding into an intracellular signal that leads to the degradation of Mth1. RESULTS: High levels of glucose induce degradation of Mth1 through the Rgt2/Snf3 glucose signaling pathway. Fluorescence microscopy analysis indicates that, under glucose-limited conditions, GFP-Mth1 is localized in the nucleus and does not shuttle between the nucleus and cytoplasm. If glucose-induced degradation is prevented due to disruption of the Rgt2/Snf3 pathway, GFP-Mth1 accumulates in the nucleus. When engineered to be localized to the cytoplasm, GFP-Mth1 is degraded regardless of the presence of glucose or the glucose sensors. In addition, removal of Grr1 from the nucleus prevents degradation of GFP-Mth1. These results suggest that glucose-induced, glucose sensor-dependent Mth1 degradation occurs in the nucleus. We also show that, like Yck2, Yck1 is localized to the plasma membrane via C-terminal palmitoylation mediated by the palmitoyl transferase Akr1. However, glucose-dependent degradation of Mth1 is not impaired in the absence of Akr1, suggesting that a direct interaction between the glucose sensors and Yck1/2 is not required for Mth1 degradation. CONCLUSION: Glucose-induced, glucose sensor-regulated degradation of Mth1 occurs in the nucleus and does not require direct interaction of the glucose sensors with Yck1/2.
@article{Pasula2010Role,
abstract = {{ABSTRACT}: {BACKGROUND}: In yeast, glucose-dependent degradation of the Mth1 protein, a corepressor of the glucose transporter gene ({HXT}) repressor Rgt1, is a crucial event enabling expression of several {HXT}. This event occurs through a signaling pathway that involves the Rgt2 and Snf3 glucose sensors and yeast casein kinase 1 and 2 (Yck1/2). In this study, we examined whether the glucose sensors directly couple with Yck1/2 to convert glucose binding into an intracellular signal that leads to the degradation of Mth1. {RESULTS}: High levels of glucose induce degradation of Mth1 through the {Rgt2/Snf3} glucose signaling pathway. Fluorescence microscopy analysis indicates that, under glucose-limited conditions, {GFP}-Mth1 is localized in the nucleus and does not shuttle between the nucleus and cytoplasm. If glucose-induced degradation is prevented due to disruption of the {Rgt2/Snf3} pathway, {GFP}-Mth1 accumulates in the nucleus. When engineered to be localized to the cytoplasm, {GFP}-Mth1 is degraded regardless of the presence of glucose or the glucose sensors. In addition, removal of Grr1 from the nucleus prevents degradation of {GFP}-Mth1. These results suggest that glucose-induced, glucose sensor-dependent Mth1 degradation occurs in the nucleus. We also show that, like Yck2, Yck1 is localized to the plasma membrane via C-terminal palmitoylation mediated by the palmitoyl transferase Akr1. However, glucose-dependent degradation of Mth1 is not impaired in the absence of Akr1, suggesting that a direct interaction between the glucose sensors and Yck1/2 is not required for Mth1 degradation. {CONCLUSION}: Glucose-induced, glucose sensor-regulated degradation of Mth1 occurs in the nucleus and does not require direct interaction of the glucose sensors with Yck1/2.},
added-at = {2018-12-02T16:09:07.000+0100},
author = {Pasula, Satish and Chakraborty, Samujjwal and Choi, Jae H. and Kim, Jeong-Ho H.},
biburl = {https://www.bibsonomy.org/bibtex/29e0335585bf053981de7e7cccc85c5f0/karthikraman},
citeulike-article-id = {6776486},
citeulike-linkout-0 = {http://dx.doi.org/10.1186/1471-2121-11-17},
citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/20205947},
citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=20205947},
day = 7,
doi = {10.1186/1471-2121-11-17},
interhash = {bd7e0f67ed8b1e7d87e3ef22c9d7c488},
intrahash = {9e0335585bf053981de7e7cccc85c5f0},
issn = {1471-2121},
journal = {BMC cell biology},
keywords = {glucose-signalling yeast},
month = mar,
number = 1,
pages = {17+},
pmid = {20205947},
posted-at = {2010-03-11 19:38:02},
priority = {2},
timestamp = {2018-12-02T16:09:07.000+0100},
title = {Role of casein kinase 1 in the glucose sensor-mediated signaling pathway in yeast.},
url = {http://dx.doi.org/10.1186/1471-2121-11-17},
volume = 11,
year = 2010
}