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ABSTRACT: APR3 (apoptosis related protein 3) is a novel gene highly conserved across species. Analysis of the data about APR3 available at GEO profiles revealed consistent and significant changes of APR3 expression level in certain developmental and inflammatory processes. Based on the search and analysis of all the submitted mRNA sequence, we postulated that the two transcripts may arise from separate promoter activities rather than previously assumed alternative splicing. Through reporter assay and PCR data, we identified the distinct promoters for the two transcripts of APR3. Furthermore, exogenous expression of a constitutively active mutant of transcription factor NFAT was able to enhance both the promoter activities of APR3. Sequential deletion of the promoter from the 5' side and mutation of the promoter suggested the functional NFAT binding sites might localize between -96 bp and -47 bp. In contrast, exogenous expression of a constitutively active mutant of the transcription factor NFkB inhibited APR3 transcription. Our data suggested that APR3 might be functionally important in certain processes under which NFAT and/or NFkappaB are/is activated.
Molecular and Cellular Biochemistry 09/2007; 302(1-2):187-94. · 2.06 Impact Factor
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Fang Yu,
Guodong Yang, Zhongliang Zhao,
Lin Ji,
Yunxin Cao,
Liyuan Bai,
Fan Lu,
Haiyan Fu,
Bo Huang,
Hua Li,
Jie Zhang,
Libo Yao,
Zifan Lu
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ABSTRACT: Human Apr3 was first cloned from HL-60 cells treated by ATRA. In this study, we further demonstrated that Apr3 could be obviously upregulated by ATRA in many other ATRA sensitive cells, suggesting a common role of Apr3 in ATRA effects. Indirect immunofluorescence assay indicates that Apr3 is a membrane protein, while its truncated form without the predicted transmembrane and intracellular domain, was likely a secreted one. Furthermore, FACS analysis showed that Apr3 overexpression could cause an obvious G1/S phase arrest which might be induced by dramatic reduction of cyclin D1 expression. Strikingly, the truncated Apr3 antagonized the negative role of Apr3 on cell cycle and cyclin D1. Taken together, our data suggest that Apr3 should play an important role in ATRA signal pathway and the predicted transmembrane and/or the intracellular domain mediates Apr3 membrane localization and is vital for the negative regulation on cell cycle and cyclin D1.
Biochemical and Biophysical Research Communications 08/2007; 358(4):1041-6. · 2.48 Impact Factor
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ABSTRACT: Restin, belonging to the melanoma-associated antigen superfamily, was firstly cloned from the differentiated HL-60 cells when induced by all-trans retinoic acid (ATRA) in our lab. Our previous results showed that restin might be correlated to cell cycle arrest. Due to the importance of p53 in the regulation of cell growth and the relationship between p53 and ATRA, we tried to test the relationship between p53 and restin. Firstly, transfection results showed that p53 was able to upregulate the expression of restin at the transcriptional level when p53 was transfected into eukaryotic cells. Secondly, the bioinformatics analysis revealed that the upstream sequence (about 2 kb) from the first ATG of the ORF of restin gene contained a p53 binding site. In order to confirm that p53 was involved in the transcriptional regulation of restin, we cloned the upstream sequence of restin and constructed the promoter luciferase reporter system. From the luciferase activity, we demonstrated that the promoter of restin gene could be induced by ATRA. Then, another two luciferase reporter plasmids driven by the reporter of restin with no (RPdelta p53-luc) or mutant (mRP-luc) p53 binding site were constructed to see the regulation of restin by p53. Results showed that the transcriptional upregulation of restin gene was not due to the putative p53 binding site on the upstream of restin gene. We proposed that p53 upregulated restin transcription through an indirect way rather than direct interaction with the cis-activating element of the restin promoter.
Science in China Series C Life Sciences 03/2007; 50(1):88-92. · 1.61 Impact Factor
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ABSTRACT: The oncoprotein c-Jun is a component of the activator protein-1 transcription factor complex, which is involved in cellular proliferation, transformation, and death. The stabilization of c-Jun is critically important for its function. The phosphorylation of c-Jun by c-Jun NH(2)-terminal kinase 1 and extracellular signal-regulated protein kinases reduces c-Jun ubiquitination resulting in increased stabilization of c-Jun. In this report, we showed that COOH-terminal Src kinase (CSK) binds with and phosphorylates c-Jun at Y26 and Y170. Phosphorylation of c-Jun by CSK, in opposition to c-Jun NH(2)-terminal kinase 1 and extracellular signal-regulated protein kinases, promoted c-Jun degradation and reduced stability. By promoting c-Jun degradation, CSK helps to maintain a low steady-state level of c-Jun, thereby inhibiting activator protein-1 activity and cell transformation caused by c-Jun. These results indicated that this function of CSK controls cell proliferation under normal growth conditions and may have implications for CSK loss of function in carcinogenesis.
Cancer Research 07/2006; 66(11):5729-36. · 7.86 Impact Factor
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ABSTRACT: Restin, a member of melanoma-associated antigen superfamily gene, was first cloned from differentiated leukemia cell induced by all trans-retinoic acid, and was able to inhibit cell proliferation, but the molecular mechanism was not clear. Since Restin was localized in cell nucleus, and its homolog member, Necdin (neuronal growth suppressor factor), could interact with transcription factors p53 and E2F1, we proposed that Restin might also function as Necdin through interacting with some transcription factors. In this study, transcription factors p53, AP1, ATFs and E2Fs were cloned and used in the mammalian two-hybrid system to identify their interaction with Restin. The results showed that only ATF3 had a strong interaction with Restin. It is interesting to know that ATF3 was an important transcription factor for G1 cell cycle initiation in physiological stress response. It was possible that the inhibition of cell proliferation by Restin might be related with the inhibition of ATF3 activity.
Science in China Series C Life Sciences 07/2005; 48(3):256-62. · 1.61 Impact Factor
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ABSTRACT: In the present study, a new member of melanoma associated antigens (Mage), named Restin (219 amino acids), was identified from HL-60 cell induced by all-trans-retinoic acid (ATRA) by PCR-based subtractive hybridization. Bioinformatics analysis found this novel gene shares high homolog with Necdin (a neuronal growth suppressor, 49%). Both of them are basic proteins. Moreover, the Restin, Necdin and Mages are in one protein superfamily. This fact indicates that the Restin and Mages are mutually related but functionally different. Further analysis found that they can be divided into two subgroups, the acid and the basic. Restin, Necdin and Mage-D1 have an alkaline conserve region (PI is from 8.6 to 10.1), which are not or less expressed in tumor tissues but mostly in normal tissues. It has been reported that Necdin can arrest the cell proliferation by interaction with p53 and E2F1. Therefore, all of them are probably related to arrest the cell cycle. However, the Mage A and C are primarily acid proteins (PI is from 4.2 to 4.9), not expressed in normal tissues but in tumors. It is quite probable that these proteins are involved in the cell proliferation. We therefore suggest that these two protein families might be a pair of control elements of cell cycle-"in cycle or out of cycle".
Science in China Series C Life Sciences 09/2002; 45(4):412-20. · 1.61 Impact Factor
