A novel transcript variant of proteasome activator 28γ: Identification and function in oral cancer cells.
Proteasome activator 28γ (PA28γ) binds to and activates the proteasome in an ATP-independent manner to promote mainly ubiquitin-independent protein degradation in cells. Previously, four transcript variants of PA28γ have been identified, which have been closely correlated with the progression of cancers. In the present study, we predicted the alternative splicing of PA28γ via the bioinformatics tool ASPicDB and 49 splices were predicted. Then, we cloned some new segment according to predication in oral cancer cells using reverse transcription PCR and a novel variant of PA28γ was found. The novel transcript encodes a truncated form compared with other isoforms of PA28γ. However, it contains most of the conserved residues and the 'activation loop' of the PA28γ family. In order to explore its function, we overexpressed the variant in HEK293 cells and demonstrated that this variant is likely to further regulate cell cycle and apoptosis via regulating p53 and the mouse double minute2 homolog (Mdm2).
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
Xiaoping
X
Xu
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
Dongjuan
D
Liu
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
Ning
N
Ji
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
Taiwen
T
Li
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
Longjiang
L
Li
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
Lu
L
Jiang
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
Jing
J
Li
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
Ping
P
Zhang
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
Xin
X
Zeng
State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, Sichuan 610041, P.R. China.
Qianming
Q
Chen
D017398:Alternative Splicing; D017209:Apoptosis; D001324:Autoantigens / Q000235:genetics* / Q000378:metabolism*; D002453:Cell Cycle; D045744:Cell Line, Tumor; D003001:Cloning, Molecular; D019295:Computational Biology / Q000379:methods*; D057809:HEK293 Cells; D006801:Humans; D009062:Mouth Neoplasms / Q000235:genetics*; D046988:Proteasome Endopeptidase Complex / Q000235:genetics* / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D051736:Proto-Oncogene Proteins c-mdm2 / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
D001324:Autoantigens; C099558:Ki antigen; D020033:Protein Isoforms; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; C497206:MDM2 protein, human; D051736:Proto-Oncogene Proteins c-mdm2; D046988:Proteasome Endopeptidase Complex