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Phthalocyanine 4 (Pc 4) photodynamic therapy of human OVCAR-3 tumor xenografts

PHOTOCHEMISTRY AND PHOTOBIOLOGY 1999年第2期69卷 236-241页

作者： Colussi, VC Feyes, DK Mulvihill, JW Li, YS Kenney, ME Elmets, CA Oleinick, NL Mukhtar, H Case Western Reserve Univ Dept Dermatol Skin Dis Res Ctr Cleveland OH 44106 USA Case Western Reserve Univ Dept Radiat Oncol Cleveland OH 44106 USA Case Western Reserve Univ Dept Chem Cleveland OH 44106 USA Univ Alabama Birmingham Dept Dermatol Birmingham AL 35294 USA

Photodynamic therapy (PDT) Is a cancer treatment modality utilizing a photosensitizer, light and oxygen. Photodynamic therapy with Photofrin(R) has been approved by the U.S. Food and Drug Administration for treatment of advanced esophageal and early lung cancer, Because of certain drawbacks associated with the use of Photofrin, there is a need to identify new photosensitizers for human use, The photosensitizer Pc 4 (HOSiPcOSi[CH3](2)[CH2](3)N[CH3](2)) has yielded promising PDT effects in many itt vitro and in vivo systems, The aim of this study was to assess the usefulness of Pc 4 as a PDT photosensitizer for a human tumor grown as a xenograft in athymic nude mice, The ovarian epithelial carcinoma (OVCAR-3) was heterotransplanted subcutaneously in athymic nude mice, Sixty mice bearing OVCAR-3 tumors (similar to 80-130 mm(3)) were divided into six groups of 10 animals each, three for controls and three for treatment, The Pc 4 was given by tail vein injection, and 48 h Later a 1 cm area encompassing the tumor was irradiated with light from a diode laser coupled to a irradiated terminating in a microlens (lambda = 672 nm, 150 J/cm(2), 150 mW/cm(2)), Tumors of control animals receiving no treatment, light alone or Pc 4 alone continued to grow, Of animals receiving 0.4 mg/kg Pc 4 and light, one (10%) had a complete response and was cured (no regrowth up to 90 days post-PDT), while all others (90%) had a partial response and were delayed in regrowth, Of animals receiving 0.6 mg/kg Pc 4 and light, eight (80%) had a complete response, and two of these were cured. Of animals receiving 1.0 mg/kg Pc 4 and light, six (60%) had a complete response, and two of these were cured, In additional experiments, tumors from animals treated with Pc 4 (1 mg/kg) and fight were removed 15, 30, 60 and 180 min post-PDT, and from these tumors DNA and protein were extracted. Agarose gel electrophoresis revealed the presence of apoptotic DNA fragmentation as early as 15 min post-PDT, Western blot

关键词：细胞凋亡/药物作用周期素依赖激酶抑制剂p21 细胞周期蛋白类/代谢吲哚类/治疗应用小鼠近交C3H 小鼠裸卵巢肿瘤/药物疗法光化学疗法光敏感药/治疗应用聚ADP核糖聚合酶类/代谢移植异种动物女(雌)性人类小鼠

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Reversible phosphorylation at the C-terminal regulatory domain of p21^Waf1/Cip1 modulates proliferating cell nuclear antigen binding

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JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第15期275卷 11529-11537页

作者： Scott, MT Morrice, N Ball, KL Univ Dundee Sch Med Canc Res Campaign Labs Dundee DD1 9SY Scotland Univ Dundee Dept Biochem MRC Prot Phosphorylat Unit Dundee DD1 5EH Scotland

The p53-inducible gene product p21(WAF1/CIP1) plays a critical role in regulating the rate of tumor incidence, and identifying mechanisms of its post-translational regulation will define key pathways that link growth control to p21-dependent tumor suppression. A eukaryotic cell model system has been developed to determine whether protein kinase signaling pathways that phosphorylate human pal exist in vivo and whether such pathways regulate the binding of p21 to one of its key target proteins, proliferating cell nuclear antigen (PCNA). Although human p21 expressed in Sf9 cells is able to form a complex with human PCNA, the inclusion of cell-permeable phosphatase inhibitors renders p21 protein inactive for PCNA binding. The treatment of this inactive isoform of p21 with alkaline phosphatase restores its binding to PCNA, suggesting that p21 expressed in Sf9 cells is subject to reversible phosphorylation at a key regulatory site(s), A biochemical approach was subsequently used to map the phosphorylation sites within p21, whose modification in vitro can inhibit p21-PCNA complex formation, to the C-terminal domain at residues Thr(145) Or Ser(146), A phospho-specific antibody was developed that only bound to full-length p21 protein after phosphorylation in vitro at Ser146, and this reagent was further used to demonstrate that the inactive isoform of p21 recovered from Sf9 cells treated with phosphatase inhibitors had been phosphorylated in vivo at Ser(146), These data identify the first phosphorylation site within the C-terminal regulatory domain of p21 whose modification in vivo modulates p21-PCNA interactions and define a eukaryotic cell model that can be used to study post-translational signaling pathways that regulate p21.

关键词：氨基酸序列环AMP依赖性蛋白激酶类/生理学细胞周期蛋白D 细胞周期蛋白依赖激酶4 周期素依赖激酶抑制剂p21 细胞周期蛋白质依赖激酶类/代谢细胞周期蛋白类/代谢分子序列数据黑软海绵素A/药理学磷酰化增殖细胞核抗原/代谢蛋白激酶C/生理学原癌基因蛋白质类丝氨酸/代谢斜纹夜蛾属动物人类

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Activation of a Plasmodium falciparum cdc2-related kinase by heterologous p25 and cyclin H -: Functional characterization of a P. falciparum cyclin homologue

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JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第12期275卷 8952-8958页

作者： Le Roch, K Sestier, C Dorin, D Waters, N Kappes, B Chakrabarti, D Meijer, L Doerig, C INSERM U511 F-75013 Paris France Walter Reed Army Med Ctr Walter Reed Army Inst Res Div Expt Therapeut Washington DC 20307 USA Heidelberg Univ Ctr Biochem D-69120 Heidelberg Germany Univ Cent Florida Dept Mol Biol & Microbiol Orlando FL 32016 USA CNRS Stn Biol Roscoff F-29682 Roscoff France

Several Plasmodium falciparum genes encoding cdc2-related protein kinases have been identified, but the modalities of their regulation remains largely unexplored. Zn the present study, we investigated the regulation in vitro of PfPK5, a putative homologue of Cdk1 (cdc2) in P. falciparum. We show that (i) PfPK5 is efficiently activated by heterologous (human) cyclin H and p25, a cyclin-like molecule that specifically activates human Cdk5;(ii) the activated enzyme can be inhibited by chemical Cdk inhibitors;(iii) Pfmrk, a putative P. falciparum homologue of the Cdk-activating kinase, does neither activate nor phosphorylate PfPK5;and (iv) PfPK5 is able to autophosphorylate in the presence of a cyclin, Taken together, these results suggest that the regulation of Plasmodium Cdks may differ in important aspects from that of their human counterparts. Furthermore, we cloned an open reading frame encoding a novel P. falciparum protein possessing maximal homology to cyclin H from various organisms, and we show that this protein, called Pfcyc-1, is able to activate recombinant PfPK5 in vitro with an efficiency similar to that of human cyclin H and p25, This work opens the way to the development of screening procedures aimed at identifying compounds that specifically target the parasite Cdks.

关键词：氨基酸序列碱基序列 CDC2蛋白激酶细胞周期蛋白H 细胞周期蛋白类/遗传学细胞周期蛋白类/代谢酶激活组蛋白类/代谢分子序列数据磷酰化恶性疟原虫/酶学恶性疟原虫/遗传学蛋白质结合原虫蛋白质类序列同源性氨基酸底物特异性动物

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Reciprocal regulation via protein-protein interaction between c-myc and p21^{cip1/waf1/sdi1} in DNA replication and transcription

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JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第14期275卷 10477-10483页

作者： Kitaura, H Shinshi, M Uchikoshi, Y Ono, T Tsurimoto, T Yoshikawa, H Iguchi-Ariga, SMM Ariga, H Hokkaido Univ Grad Sch Pharmaceut Sci Kita Ku Sapporo Hokkaido 0600812 Japan Hokkaido Univ Coll Med Technol Kita Ku Sapporo Hokkaido 0600812 Japan Nara Inst Sci & Technol Fac Biol Sci Nara 6300101 Japan

The c-myc protooncogene product (c-Myc) is a transcription factor and is rapidly induced in resting cells following various mitogenic stimuli. c-Myc is thus suggested to play an important role in the transition from quiescence to proliferation. Despite numerous studies, including those on the connection between cyclin E/cyclin-dependent kinase 2 and c-Myc, little has been clarified about c-Myc in terms of the cell cycle regulation. Here we show that c-Myc can directly bind to the carboxyl-terminal region of the cyclin-dependent kinase inhibitor p(21cip1/waf1/sdi1) and thus partially relieves the p21 of the inhibitory effect on DNA synthesis directed by the proliferating cell nuclear antigen-dependent DNA polymerase delta. As for transcription, on the other hand, the p21 binding to the Myc box II region of c-Myc blocks c-Myc-Max complex formation on the E-box and thereby suppresses the transcriptional activation from the E-box by c-Myc. These results suggest that c-Myc activates DNA replication via inactivation of p21 and that p21, vice versa, represses the transcriptional activity of c-Myc. The balance of the reciprocal inactivation between c-Myc and p21 may determine the course of cellular processes such as cell proliferation, differentiation, and apoptosis.

关键词：结合部位结合竞争性克隆分子周期素依赖激酶抑制剂p21 细胞周期蛋白类/分离和提纯细胞周期蛋白类/代谢 DNA复制酶抑制剂/代谢大肠杆菌基因 myc 增殖细胞核抗原/代谢原癌基因蛋白质c-myc/化学原癌基因蛋白质c-myc/分离和提纯原癌基因蛋白质c-myc/代谢重组融合蛋白质类/代谢重组蛋白质类/化学重组蛋白质类/分离和提纯重组蛋白质类/代谢转录遗传

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Building a replisome from interacting pieces: Sliding clamp complexed to a peptide from DNA polymerase and a polymerase editing complex

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CELL 1999年第2期99卷 155-166页

作者： Shamoo, Y Steitz, TA Yale Univ Dept Mol Biophys & Biochem New Haven CT 06520 USA Yale Univ Dept Chem New Haven CT 06520 USA Yale Univ Howard Hughes Med Inst New Haven CT 06520 USA

We have solved the crystal structures of the bacteriophage RB69 sliding clamp, its complex with a peptide essential for DNA polymerase interactions, and the DNA polymerase complexed with primer-template DNA. The editing complex structure shows a partially melted duplex DNA exiting from the exonuclease domain at an unexpected angle and significant changes in the protein structure. The clamp complex shows the C-terminal 11 residues of polymerase bound in a hydrophobic pocket, and it allows docking of the editing and clamp structures together. The peptide binds to the sliding clamp at a position identical to that of a replication inhibitor peptide bound to PCNA, suggesting that the replication inhibitor protein p21(CIP1) functions by competing with eukaryotic polymerases for the same binding pocket on the clamp.

关键词：氨基酸序列细菌噬菌体/遗传学结合部位结晶学 X线周期素依赖激酶抑制剂p21 细胞周期蛋白类/代谢 DNA复制 DNA 病毒/化学 DNA 病毒/代谢指导DNA的DNA聚合酶/化学指导DNA的DNA聚合酶/代谢模型分子分子序列数据核酸构象核酸变性作用增殖细胞核抗原/化学增殖细胞核抗原/代谢蛋白质构象蛋白质结构二级模板遗传

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Requirement for a kinase-specific chaperone pathway in the production of a Cdk9/cyclin T1 heterodimer responsible for P-TEFb-mediated tat stimulation of HIV-1 transcription

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JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第1期275卷 279-287页

作者： O'Keeffe, B Fong, Y Chen, D Zhou, S Zhou, Q Univ Calif Berkeley Dept Mol & Cell Biol Berkeley CA 94720 USA

Tat activation of HIV-1 transcription is mediated by human transcription elongation factor P-TEFb, which interacts with Tat and phosphorylates the C-terminal domain of RNA polymerase II. The catalytic subunit of the P-TEFb complex, Cdk9, has been shown to interact with cyclin T and several other proteins of unknown identity, Consequently, the exact subunit composition of active P-TEFb has not been determined. Here we report the affinity purification and identification of the Cdk9 associated proteins. In addition to forming a heterodimer with cyclin T1, Cdk9 interacted with the molecular chaperone Hsp76 or a kinase-specific chaperone complex, Hsp90/Cdc37, to form two separate chaperone-Cdk9 complexes, Although the Cdk9/cyclin T1 dimer was exceptionally stable and produced slowly in the cell, free and unprotected Cdk9 appeared to be degraded rapidly, Several lines of evidence indicate the heterodimer of Cdk9/cyclin T1 to be the mature, active form of P-TEFb responsible for phosphorylation of the C-terminal domain of RNA polymerase II interaction with the Tat activation domain, and mediation of Tat activation of HIV-1 transcription. Pharmacological inactivation of Hsp90/Cdc37 function by geldanamycin revealed an essential role for the chaperone-Cdk9 complexes in generation of Cdk9/cyclin TI, Our data suggest a previously unrecognized chaperone-dependent pathway involving the sequential actions of Hsp70 and Hsp90/Cdc37 in the stabilization/folding of Cdk9 as well as the assembly of an active Cdk9/cyclin T1 complex responsible for P-TEFb-mediated Tat transactivation.

关键词：苯醌类细胞周期蛋白质类/代谢伴侣蛋白类细胞周期蛋白T 细胞周期蛋白依赖激酶9 细胞周期蛋白质依赖激酶类/代谢细胞周期蛋白类/代谢 DNA聚合酶Ⅱ/代谢二聚作用果蝇蛋白质类酶激活基因产物 tat/代谢 HIV-1/遗传学 HSP70热休克蛋白质类/代谢 HSP90热休克蛋白质类/代谢内酰胺类大环分子伴侣/代谢阳性转录延伸因子B 蛋白质结合/药物作用蛋白质丝氨酸苏氨酸激酶/代谢醌类/药理学种特异性转录遗传 tat基因产物人免疫缺陷病毒人类

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Distinct roles for PP1 and PP2A in phosphorylation of the retinoblastoma protein -: PP2A regulates the activities of G₁ cyclin-dependent kinases

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JOURNAL OF BIOLOGICAL CHEMISTRY 1999年第45期274卷 31917-31924页

作者： Yan, Y Mumby, MC Univ Texas SW Med Ctr Dept Pharmacol Dallas TX 75235 USA

The function of the retinoblastoma protein (pRB) in controlling the G(1) to S transition is regulated by phosphorylation and dephosphorylation on serine and threonine residues. While the roles of cyclin-dependent kinases in phosphorylating and inactivating pRB have been characterized in detail, the roles of protein phosphatases in regulating the G(1)/S transition are not as well understood. We used cell-permeable inhibitors of protein phosphatases 1 and 2A to assess the contributions of these phosphatases in regulating cyclin-dependent kinase activity and pRB phosphorylation, Treating asynchronously growing Balb/c 3T3 cells with PP2A-selective concentrations of either okadaic acid or calyculin A caused a time- and dose-dependent decrease in PRE phosphorylation, Okadaic acid and calyculin A had no effect on pRB phosphatase activity even though PP2A was completely inhibited. The decrease in pRB phosphorylation correlated with inhibitor-induced suppression of G(1) cyclin dependent kinases including CDK2, CDK4, and CDK6. The inhibitors also caused decreases in the levels of cyclin D2 and cyclin E, and induction of the cyclin-dependent kinase inhibitors p21(Cip1) and p27(Kip1). The decrease in cyclin dependent kinase activities were not dependent on induction of cyclin-dependent kinase inhibitors since CDK inhibition still occurred in the presence of actinomycin D or cycloheximide. In contrast, selective inhibition of protein phosphatase 1 with tautomycin inhibited pRB phosphatase activity and maintained pRB in a highly phosphorylated state. The results show that protein phosphatase 1 and protein phosphatase 2A, or SA-like phosphatases, play distinct roles in regulating PRE function. Protein phosphatase 1 is associated with the direct dephosphorylation of pRB while protein phosphatase ZA is involved in pathways regulating G(1) cyclin-dependent kinase activity.

关键词： 3T3细胞抗真菌药/药理学细胞周期蛋白G 细胞周期蛋白G1 细胞周期蛋白质依赖激酶类/代谢细胞周期蛋白类/代谢酶抑制剂/药理学同工酶类/代谢小鼠近交BALBC 黑软海绵素A/药理学恶唑类/药理学磷蛋白磷酸酶类/代谢磷酰化蛋白质磷酸酶1 蛋白质磷酸酶2 吡喃类视网膜母细胞瘤蛋白质/代谢螺环化合物动物小鼠

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Expression of cyclin-dependent kinase inhibitor p27^Kip1 in AIDS-related diffuse large-cell lymphomas is associated with Epstein-Barr virus-encoded latent membrane protein 1

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AMERICAN JOURNAL OF PATHOLOGY 2002年第1期161卷 163-171页

作者： Gloghini, A Gaidano, G Larocca, LM Pierconti, F Cingolani, A Dal Maso, L Capello, D Franceschi, S Tirelli, U Libra, M Niu, HF Dalla-Favera, R Carbone, A Ist Nazl Tumori Div Pathol Ctr Riferimento Oncol Ist Ricovero & Cura Carattere Sci I-33081 Aviano Italy Ist Nazl Tumori Div Epidemiol Ctr Riferimento Oncol Ist Ricovero & Cura Carattere Sci I-33081 Aviano Italy Ist Nazl Tumori Div Med Oncol Ctr Riferimento Oncol Ist Ricovero & Cura Carattere Sci I-33081 Aviano Italy Ist Nazl Tumori AIDS Program Ctr Riferimento Oncol Ist Ricovero & Cura Carattere Sci I-33081 Aviano Italy Amedeo Avogadro Univ Eastern Piedmont Dept Med Sci Div Internal Med Hematol Unit Novara Italy Univ Cattolica Sacro Cuore Inst Pathol Rome Italy Univ Cattolica Sacro Cuore Inst Infect Dis Rome Italy Univ Catania Dept Biomed Sci I-95124 Catania Italy Univ Catania Mol Oncol Sect I-95124 Catania Italy Columbia Univ Inst Canc Genet New York NY USA

Knowledge of the role of cell-cycle regulators in the pathogenesis of acquired immune deficiency syndrome-related non-Hodgkin's lymphomas (AIDS-NHLs) is scarce. Here we analyzed 86 systemic AIDS-NHLs and 20 AIDS-primary central nervous system lymphomas for expression of p27(Kip1), a negative regulator of cell-cycle progression belonging to the Kip family of cyclin-dependent kinase inhibitors. In parallel, we investigated the relationship between p27(Kip1), the lymphoma proliferation index, Epstein-Barr virus status, expression of cellular cyclin D3 and cyclin D1, and B-cell differentiation stage. We report that AIDS-immunoblastic lymphomas (AIDS-IBLs), either systemic or primarily localized to the central nervous system, consistently express p27(Kip1) protein (19 of 24 and 10 of 14, respectively) despite the high proliferative rate of the lymphoma clone, suggesting a failure of P27(Kip1) to inhibit the cell cycle in AIDS-IBL. Conversely, the remaining systemic AIDS-NHLs and AIDS-primary central nervous system lymphomas preferentially fail to express p27(Kip1). Expression of p27(Kip1) in Epstein-Barr virus-positive AIDS-NHLs generally associates with latent membrane protein 1 (LMP1) expression and is related to a late stage of B-cell differentiation, characterized by the BCL-6-/MUM1+/syn-1 +/- phenotypic profile, whereas it seems;to be unrelated to the expression of cellular cyclins. In B cells in vitro, induction of LMP-1 expression under the control of inducible promoters up-regulates expression of p27(Kip1), thus providing a putative mechanistic explanation for the association between LMP1 and p27(Kip1) observed in vivo. Overall, these data show that AIDS-IBL pathogenesis is characterized by loss of the inverse relationship between p27(Kip1) positivity and tumor growth fraction that is otherwise generally observed in normal lymphoid tissues and in most other types of NHLs.

关键词：拟南芥蛋白质类 B淋巴细胞/病理学细胞周期蛋白质类/代谢细胞分化细胞周期蛋白D1/代谢细胞周期蛋白D3 周期素依赖激酶抑制剂p27 细胞周期蛋白类/代谢 DNA结合蛋白质类/代谢干扰素调节因子类 Ki-67抗原/代谢淋巴组织/代谢淋巴瘤艾滋病相关/代谢淋巴瘤艾滋病相关/病理学淋巴瘤大B细胞弥漫性/代谢淋巴瘤大B细胞弥漫性/病理学淋巴瘤非霍奇金/遗传学淋巴瘤非霍奇金/代谢肿瘤分期表型植物蛋白质类原癌基因蛋白质类/代谢原癌基因蛋白质c-bcl-6 转录因子/代谢肿瘤抑制蛋白质类/代谢病毒基质蛋白质类/代谢人类

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Isolation of Trypanosoma brucei CYC2 and CYC3 cyclin genes by rescue of a yeast G₁ cyclin mutant -: Functional characterization of CYC2

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JOURNAL OF BIOLOGICAL CHEMISTRY 2000年第12期275卷 8315-8323页

作者： Van Hellemond, JJ Neuville, P Schwarz, RT Matthews, KR Mottram, JC Univ Glasgow Wellcome Ctr Mol Parasitol Anderson Coll Glasgow G11 6NU Lanark Scotland Univ Marburg Zentrum Hyg & Med Mikrobiol D-35037 Marburg Germany Univ Manchester Sch Biol Sci Manchester M13 9PT Lancs England

Two Trypanosoma brucei cyclin genes, CYC2 and CYC3, have been isolated by rescue of the Saccharomyces cerevisiae mutant DL1, which is deficient in CLN G(1) cyclin function. CYC2 encodes a 24-kDa protein that has sequence identity to the Neurospora crassa PREG1 and the S. cerevisiae PHO80 cyclin. CYC3 has the most sequence identity to mitotic B-type cyclins from a variety of organisms. Both CYC2 and CYC3 are single-copy genes and expressed in all life cycle stages of the parasite. To determine if CYC2 is found in a complex with previously identified trypanosome cdc2-related kinases (CRKs), the CYC2 gene was fused to the TY epitope tag, integrated into the trypanosome genome, and expressed under inducible control. CYC2ty was found to associate with an active trypanosome CRK complex since CYC2ty bound to leishmanial p12(cks1), and histone H1 kinase activity was detected in CYC2ty immune-precipitated fractions. Gene knockout experiments provide evidence that CYC2 is an essential gene, and co-immune precipitations together with a two-hybrid interaction assay demonstrated that CYC2 interacts with CRK3. The CRK3 . CYC2ty complex, the first cyclin-dependent kinase complex identified in trypanosomes, was localized by immune fluorescence to the cytoplasm throughout the cell cycle.

关键词：氨基酸序列细胞区室化细胞周期蛋白质类细胞周期蛋白G 细胞周期蛋白质依赖激酶类/分离和提纯细胞周期蛋白质依赖激酶类/代谢细胞周期蛋白类/遗传学细胞周期蛋白类/代谢真菌蛋白质类/代谢基因原虫遗传互补测验分子序列数据突变蛋白质结合原虫蛋白质类/遗传学原虫蛋白质类/代谢酿酒酵母菌/遗传学非洲粟酒人体酵母蛋白质类序列同源性氨基酸布鲁斯锥虫布鲁斯亚种/遗传学双杂交系统技术动物

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Tobacco retinoblastoma-related protein phosphorylated by a distinct cyclin-dependent kinase complex with Cdc2/cyclin D in vitro

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PLANT JOURNAL 1999年第3期18卷 243-252页

作者： Nakagami, H Sekine, M Murakami, H Shinmyo, A Nara Inst Sci & Technol Grad Sch Biol Sci Nara 6300101 Japan

The retinoblastoma (Rb) protein was originally identified as a product of a tumour suppressor gene that plays a pivotal role in regulating both the cell cycle and differentiation in mammals. The growth-suppressive activity of Rb is regulated by phosphorylation with cyclin-dependent kinase (CDK), and inactivation of the Rb function is one of the critical steps for transition from the G1 to the S phase. We report here the cloning of a cDNA (NtRb1) from Nicotiana tabacum which encodes a Rb-related protein, and show that this gene is expressed in all the organs examined at the mRNA level. We have demonstrated that NtRb1 interacts with tobacco cyclin D by using yeast two-hybrid and in vitro binding assays. In mammals, cyclin D can assemble with CDK4 and CDK6, but not with Cdc2, to form active complexes. Surprisingly, tobacco cyclin D and Cdc2 proteins can form a complex in insect cells, which is able to phosphorylate tobacco Rb-related protein in vitro. Using immunoprecipitation with the anti-cyclin D antibody, cyclin D can be found in a complex with Cdc2 in suspension-cultured tobacco BY-2 cells. These results suggest that the cdc2 gene modulates the cell cycle through the phosphorylation of Rb-related protein by forming an active complex with cyclin D in plants.

关键词：氨基酸序列碱基序列 CDC2蛋白激酶/代谢细胞周期蛋白质类细胞周期蛋白质依赖激酶类/代谢细胞周期蛋白类/代谢 DNA引物/遗传学 DNA 互补/遗传学 DNA 互补/分离和提纯基因表达基因植物大分子物质分子序列数据磷酰化植物蛋白质类/遗传学植物蛋白质类/代谢植物有毒重组融合蛋白质类/遗传学重组融合蛋白质类/代谢视网膜母细胞瘤蛋白质/遗传学视网膜母细胞瘤蛋白质/代谢序列同源性氨基酸烟草/遗传学烟草/代谢动物人类

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