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Regulation of glycogen synthase kinase 3beta functions by modification of the small ubiquitin-like modifier.

Eun Jeoung L, Sung Hee H, Jaesun C, Sung Hwa S, Kwang Hum Y, Min Kyoung K, Tae Yoon P, Sang Sun K - Open Biochem J (2008)

Bottom Line: In this report, we showed that the SUMOylation of GSK 3beta occurs on its K(292) residue, and this modification promotes its nuclear localization in COS-1.Additionally, our data showed that the GSK 3beta SUMO mutant (K292R) decreased its kinase activity and protein stability, affecting cell death.Therefore, our observations at first time suggested that SUMOylation on the K(292) residue of GSK 3beta might be a GSK 3beta regulation mechanism for its kinase activation, subcellular localization, protein stability, and cell apoptosis.

View Article: PubMed Central - PubMed

Affiliation: School of Science Education, Chungbuk National University, Gaeshin-dong, Heungdok-gu, Cheongju, Chungbuk, 361-763, Republic of Korea.

ABSTRACT
Modification of the Small Ubiquitin-like Modifier (SUMO) (SUMOylation) appears to regulate diverse cellular processes, including nuclear transport, signal transduction, apoptosis, autophagy, cell cycle control, ubiquitin-dependent degradation and gene transcription. Glycogen synthase kinase 3beta (GSK 3beta) is a serine/threonine kinase that is thought to contribute to a variety of biological events, including embryonic development, metabolism, tumorigenesis, and cell death. GSK 3beta is a constitutively active kinase that regulates many intracellular signaling pathways by phosphorylating substrates such as beta-catenin. We noticed that the putative SUMOylation sites are localized on K(292 )residueof (291)FKFPQ(295) in GSK 3beta based on analysis of the SUMOylation consensus sequence. In this report, we showed that the SUMOylation of GSK 3beta occurs on its K(292) residue, and this modification promotes its nuclear localization in COS-1. Additionally, our data showed that the GSK 3beta SUMO mutant (K292R) decreased its kinase activity and protein stability, affecting cell death. Therefore, our observations at first time suggested that SUMOylation on the K(292) residue of GSK 3beta might be a GSK 3beta regulation mechanism for its kinase activation, subcellular localization, protein stability, and cell apoptosis.

No MeSH data available.


Related in: MedlinePlus

Confocal microscopic analysis of transfected Ha –GSK 3β wt (A), Ha –GSK 3β SUMO mutant (K292R) (B) was performed to determine whether it merged with SUMO-1 (red color). All Ha –GSK 3β constructs were shown as green color. The transfected Ha -GSK 3β wt (de-tected in both the cytoplasm and the nucleus) merged (yellow) with SUMO-1 in the nucleus (A). The transfected Ha –GSK 3β SUMO mutant was detected in the cytoplasm, but not in the nucleus (B). The SUMO-1 modification proteins were mainly detected in the nuclear region (B middle lane). GSK 3β SUMO mutant in which the SUMOylation site was eliminated was not merged with SUMO-1 in the nucleus (B right lane).
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Figure 3: Confocal microscopic analysis of transfected Ha –GSK 3β wt (A), Ha –GSK 3β SUMO mutant (K292R) (B) was performed to determine whether it merged with SUMO-1 (red color). All Ha –GSK 3β constructs were shown as green color. The transfected Ha -GSK 3β wt (de-tected in both the cytoplasm and the nucleus) merged (yellow) with SUMO-1 in the nucleus (A). The transfected Ha –GSK 3β SUMO mutant was detected in the cytoplasm, but not in the nucleus (B). The SUMO-1 modification proteins were mainly detected in the nuclear region (B middle lane). GSK 3β SUMO mutant in which the SUMOylation site was eliminated was not merged with SUMO-1 in the nucleus (B right lane).

Mentions: Next, we indented to determine the biological significance of SUMOylation on K292 of GSK 3βBecause the confocal microscopy results in Fig. (1D) suggested that SUMOylation of GSK 3β occur in the nuclear region, we first determined whether SUMOylation of GSK 3β affects its subcellular localization. We performed the confocal microscopic analysis with Ha -GSK 3β wt or the SUMO mutant construct, as described in Fig. (1A). The transfected Ha –GSK 3β wt or Ha –GSK 3β SUMO mutant (K292R) was detected as green and the SUMO-1 position was detected as red using fluorescence microscopy (Fig. 3). Similar to the results shown in Fig. (1D), SUMO-1 signals were mainly detected in the nucleus (Fig. 3A middle lane). Ha -GSK 3β wt was observed in both the cytoplasm and nucleus, similar to the results shown in Fig. (1D). However, the merged between GSK 3β with SUMO-1 (yellow color) was detected in the nucleus and not the cytoplasm (Fig. 3A right lane), suggesting that SUMOylation of GSK 3β is related to its nuclear subcellular localization. This result also supports the idea that GSK 3β is one of the SUMOylation proteins, consistent with the results presented in Fig. (1D).


Regulation of glycogen synthase kinase 3beta functions by modification of the small ubiquitin-like modifier.

Eun Jeoung L, Sung Hee H, Jaesun C, Sung Hwa S, Kwang Hum Y, Min Kyoung K, Tae Yoon P, Sang Sun K - Open Biochem J (2008)

Confocal microscopic analysis of transfected Ha –GSK 3β wt (A), Ha –GSK 3β SUMO mutant (K292R) (B) was performed to determine whether it merged with SUMO-1 (red color). All Ha –GSK 3β constructs were shown as green color. The transfected Ha -GSK 3β wt (de-tected in both the cytoplasm and the nucleus) merged (yellow) with SUMO-1 in the nucleus (A). The transfected Ha –GSK 3β SUMO mutant was detected in the cytoplasm, but not in the nucleus (B). The SUMO-1 modification proteins were mainly detected in the nuclear region (B middle lane). GSK 3β SUMO mutant in which the SUMOylation site was eliminated was not merged with SUMO-1 in the nucleus (B right lane).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2570553&req=5

Figure 3: Confocal microscopic analysis of transfected Ha –GSK 3β wt (A), Ha –GSK 3β SUMO mutant (K292R) (B) was performed to determine whether it merged with SUMO-1 (red color). All Ha –GSK 3β constructs were shown as green color. The transfected Ha -GSK 3β wt (de-tected in both the cytoplasm and the nucleus) merged (yellow) with SUMO-1 in the nucleus (A). The transfected Ha –GSK 3β SUMO mutant was detected in the cytoplasm, but not in the nucleus (B). The SUMO-1 modification proteins were mainly detected in the nuclear region (B middle lane). GSK 3β SUMO mutant in which the SUMOylation site was eliminated was not merged with SUMO-1 in the nucleus (B right lane).
Mentions: Next, we indented to determine the biological significance of SUMOylation on K292 of GSK 3βBecause the confocal microscopy results in Fig. (1D) suggested that SUMOylation of GSK 3β occur in the nuclear region, we first determined whether SUMOylation of GSK 3β affects its subcellular localization. We performed the confocal microscopic analysis with Ha -GSK 3β wt or the SUMO mutant construct, as described in Fig. (1A). The transfected Ha –GSK 3β wt or Ha –GSK 3β SUMO mutant (K292R) was detected as green and the SUMO-1 position was detected as red using fluorescence microscopy (Fig. 3). Similar to the results shown in Fig. (1D), SUMO-1 signals were mainly detected in the nucleus (Fig. 3A middle lane). Ha -GSK 3β wt was observed in both the cytoplasm and nucleus, similar to the results shown in Fig. (1D). However, the merged between GSK 3β with SUMO-1 (yellow color) was detected in the nucleus and not the cytoplasm (Fig. 3A right lane), suggesting that SUMOylation of GSK 3β is related to its nuclear subcellular localization. This result also supports the idea that GSK 3β is one of the SUMOylation proteins, consistent with the results presented in Fig. (1D).

Bottom Line: In this report, we showed that the SUMOylation of GSK 3beta occurs on its K(292) residue, and this modification promotes its nuclear localization in COS-1.Additionally, our data showed that the GSK 3beta SUMO mutant (K292R) decreased its kinase activity and protein stability, affecting cell death.Therefore, our observations at first time suggested that SUMOylation on the K(292) residue of GSK 3beta might be a GSK 3beta regulation mechanism for its kinase activation, subcellular localization, protein stability, and cell apoptosis.

View Article: PubMed Central - PubMed

Affiliation: School of Science Education, Chungbuk National University, Gaeshin-dong, Heungdok-gu, Cheongju, Chungbuk, 361-763, Republic of Korea.

ABSTRACT
Modification of the Small Ubiquitin-like Modifier (SUMO) (SUMOylation) appears to regulate diverse cellular processes, including nuclear transport, signal transduction, apoptosis, autophagy, cell cycle control, ubiquitin-dependent degradation and gene transcription. Glycogen synthase kinase 3beta (GSK 3beta) is a serine/threonine kinase that is thought to contribute to a variety of biological events, including embryonic development, metabolism, tumorigenesis, and cell death. GSK 3beta is a constitutively active kinase that regulates many intracellular signaling pathways by phosphorylating substrates such as beta-catenin. We noticed that the putative SUMOylation sites are localized on K(292 )residueof (291)FKFPQ(295) in GSK 3beta based on analysis of the SUMOylation consensus sequence. In this report, we showed that the SUMOylation of GSK 3beta occurs on its K(292) residue, and this modification promotes its nuclear localization in COS-1. Additionally, our data showed that the GSK 3beta SUMO mutant (K292R) decreased its kinase activity and protein stability, affecting cell death. Therefore, our observations at first time suggested that SUMOylation on the K(292) residue of GSK 3beta might be a GSK 3beta regulation mechanism for its kinase activation, subcellular localization, protein stability, and cell apoptosis.

No MeSH data available.


Related in: MedlinePlus