Effect of 14-3-3 protein induction on cell proliferation of A549 human lung adenocarcinoma

We have previously shown that 14-3-3 protein, amultifunctional adaptor molecule involved in many aspects ofsignal transduction pathways, is a target antigen for thecancer-associated human monoclonal antibody. Although recentevidences suggest a crucial role of 14-3-3 family members inthe control of cell growth and differentiation, their actualcontribution toward tumor development is still controversial. Inthis article, we examined the effect of enforced 14-3-3overexpression on cell growth of the human lung adenocarcinomacell line, A549. To address this issue, we obtained14-3-3 protein-inducible A549 sublines by transfection with14-3-3 expression vector under the control ofdexamethasone-inducible promoter. We found that 14-3-3 proteininduction in some of these sublines promoted their cell proliferation. Microscopic observation revealed that morphologyof these cells became aggressive multilayer condition,suggesting that malignant phenotypes are also acquired uponectopic induction of 14-3-3 protein.     

Mutagenicity of BCNU and related chloroethylnitrosoureas in Drosophila.

BCNU and 10 related chloroethylnitrosoureas were tested for their ability to induce sex-linked recessive lethals in Drosophila spermatozoa. All chloroethylnitrosoureas tested were potent mutagens. Among the substances with one chloroethylnitrosourea group, chlorozotocin, BCNU and methanesulfonyloxyethyl chloroethylnitrosourea exhibited the strongest mutagenic effects. Two hydroxyalkyl chloroethylnitrosoureas behaved as potent mutagens too, although the mutation frequencies obtained were one order of magnitude lower relative to the other substances. Among the compounds with two chloroethylnitrosourea groups, bisCNU-ethane and bisCNU-diphenylmethane were most active. When the interconnecting polymethylene chain was elongated from 2 methylene groups (bisCNU-ethane) to 6 methylene groups (bisCNU-hexane), the mutagenic activity decreased by a factor of 2. The mutagenic activity of polymethylene bischloroethylnitrosoureas with connecting chains of intermediate length was not different from bisCNU-hexane. Differences in mutagenic activity were supposed to reflect different concentrations reaching the target cells, possibly in part as a result of differences in transportability of the substances.     

Analysis of mutagenic activity and ability to induce replication of polyoma DNA sequences by different model metabolites of the carcinogenic tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone.

The tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) requires metabolic activation to express its carcinogenic activity. This activation leads to the formation of methylating and pyridyloxobutylating agents. To determine the possible biological effects mediated by each of these metabolic pathways we have studied the activities of model compounds that are metabolized to either a methylating or pyridyloxobutylating species. Each model compound was evaluated for its mutagenic activity in both prokaryotic and eukaryotic cell systems. The model compounds were also tested for their ability to induce asynchronous replication of viral DNA sequences. We demonstrate here that both the methylating model compound acetoxymethylmethylnitrosamine (AMMN) and the pyridyloxobutylating model compound 4-(acetoxymethyl)-1-(3-pyridyl)-1-butanone (NNKOAc) were mutagenic in strains TA98, TA100, and TA1535 but not TA102. While NNKOAc appeared to be 10 times more potent than AMMN in Salmonella, AMMN was found to be a more potent mutagen in mammalian G12 cells. Both chemicals could induce asynchronous replication of polyoma DNA sequences in rat fibroblast cells carrying an integrated copy of the polyoma virus with AMMN appearing to be more active. Measurement of DNA adduct levels suggest that the damage produced by NNKOAc was at least as active as that produced by AMMN when viewed on a per adduct basis. The possible implications of the biological activities exhibited by methylating and pyridyloxobutylating model compounds to NNK induced carcinogenesis are discussed.     

Mechanism of Cellular 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) Reduction

Abstract: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction is one of the most frequently used methods for measuring cell proliferation and neural cytotoxicity. It is widely assumed that MTT is reduced by active mitochondria in living cells. By using isolated mitochondria from rat brain and B12 cells, we indeed found that malate, glutamate, and succinate support MTT reduction by isolated mitochondria. However, the data presented in this study do not support the exclusive role of mitochondria in MTT reduction by intact cells. Using a variety of approaches, we found that MTT reduction by B12 cells is confined to intracellular vesicles that later give rise to the needle-like MTT formazan at the cell surface. Some of these vesicles were identified as endosomes or lysosomes. In addition, MTT was found to be membrane impermeable. These and other results suggest that MTT is taken up by cells through endocytosis and that reduced MTT formazan accumulates in the endosomal/lysosomal compartment and is then transported to the cell surface through exocytosis.     

MiR-126-3p inhibits ovarian cancer proliferation and invasion via targeting PLXNB2

Ovarian cancer is one of the leading malignancies in women and the 5-year survival rate of ovarian cancer still remains poor. In the present study, we aimed to investigate the interaction between the miR-126-3p and PLXNB2 in the progression of ovarian cancer. The qRT-PCR data revealed a reduction of miR-126-3p level in ovarian cancer tissues comparing to the adjacent normal tissues. Over-expression of miR-126-3p in ovarian cancer cells suppressed cell proliferation and invasion and the phosphorylation of AKT and ERK1/2. The cell cycle assay results showed that the over-expression of miR-126-3p induced cells in G1-phase and reduced cells in S-phase. We further performed bioinformatics analysis and luciferase assay to investigate the relationship between miR-126-3p and PLXNB2 in ovarian cancer cells. The results of TargetScan suggested that PLXNB2 is a direct target of miR-126-3p in ovarian cancer cells, and luciferase assay confirmed bioinformatics prediction. Knocking down of PLXNB2 with PLXNB2 siRNA results in repressed ovarian cancer cell proliferation and invasion, and decreased phosphorylation of AKT and ERK1/2, which is similar to the effect of over-expression of miR-126-3p in OC cells. The synergistic effect of combination of miR-126-3p over-expression and PLXNB2 down-regulation on the cell growth viability, cell colony, and cell invasion was also identified. All these findings indicated that miR-126-3p is involved in the progression of ovarian cancer via direct regulating PLXNB2.     

In vitro transformation by bromodeoxyuridine and X irradiation in C3H 10T1/2 cells

The effect of 10(-5) M bromodeoxyuridine (BrdUrd) substitution in C3H 10T1/2 cells was evaluated. Cellular toxicity increased rapidly for BrdUrd exposure times that were longer than the population doubling time. Radiosensitization by BrdUrd exposure was almost complete after one cell doubling time and was characterized by a decrease in D0 and the survival curve shoulder. Exposure to BrdUrd for one cell doubling time produced only very low transformation levels, but for prolonged BrdUrd exposure times, the transformation frequency per viable cell increased significantly. BrdUrd incorporation also enhanced radiation induction of transformation above the transformation levels resulting from the independent action of X rays or BrdUrd treatment. These results show that BrdUrd is a transforming agent in C3H 10T1/2 cells and thus may be a carcinogen and that BrdUrd can enhance radiation-induced transformation.     

白念珠菌14-3-3蛋白Bmh1在细胞生长和菌丝发育中的功能解析

【目的】应用Tet-off启动子研究白念珠菌唯一的14-3-3蛋白Bmh1在白念珠菌生长和菌丝发育过程中的功能。【方法】在白念珠菌URA3+菌株SN152中,我们敲除了1个BMH1基因拷贝,并用Tet-off启动子替代另一个BMH1基因拷贝的启动子,得到了可以用强力霉素(Doxycycline)控制Bmh1表达水平的菌株。然后我们通过斑点试验和形态学观察对该菌株的生长和菌丝发育表型进行了分析。通过在ras1、flo8、efg1、cph1、tec1等重要菌丝发育调控因子突变体中过表达Bmh1,我们初步研究了Bmh1在菌丝发育调控网络中的位置。最后,我们构建了一些不同C末端的Bmh1嵌合体并检测了其对白念珠菌生长和菌丝发育的影响。【结果】Doxycycline诱导Bmh1表达水平下调时严重抑制了细胞的生长。非Doxycycline诱导条件下Bmh1高表达强烈促进了细胞的菌丝发育。这一促进作用绕过了ras1、efg1、cph1和tec1等基因缺失的影响,却被flo8基因的缺失阻断。C末端缺失或更换异源C末端的所有Bmh1突变株在Doxycycline诱导时都能够正常生长,但是没有明显促进菌丝发育。【结论】验证了白念珠菌14-3-3蛋白Bmh1是细胞生长所必需的,证明了Tet-off启动子可以严密控制Bmh1的表达水平。Bmh1是一个菌丝发育的正调控因子,位于Ras1、Efg1、Cph1和Tec1的下游,Flo8的上游。Bmh1的保守结构域是细胞生长所必需的,而C末端则是生长非必需的。     

A fluence response study of lethality and mutagenicity of white, black, and blue fluorescent light, sunlamp, and sunlight irradiation in Chinese hamster ovary cells

Under a set of defined experimental conditions, the fluence response of Chinese hamster ovary (CHO) cells to various light sources was studied by measuring single-cell survival and mutation to 6-thioguanine (TG) resistance. Fluorescent white, black, and blue lights were sightly lethal and mutagenic. Sunlamp light was highly lethal and mutagenic, exhibiting these biological effects within 15 sec of exposure under conditions recommended by the manufacturer for human use. Lethal and mutagenic effects were observed after 5 min of sunlight exposure; responses varied with hourly and daily variations in solar radiation. Sunlight-induced TG-resistant variants possessed less than 5% of parental cellular hypoxanthine--guanine phosphoribosyl transferase (HGPRT) enzyme activity, suggesting that the mutation induction occurs at this locus. The cell survival and mutation-induction curves generated by exposure of cells to both sunlamp and sunlight were similar to those obtained by the use of a standard far-UV lamp.     

α3β1 integrin promotes cell survival via multiple interactions between 14-3-3 isoforms and proapoptotic proteins

Laminin-5 and α3β1 integrin promote keratinocyte survival; however, the downstream signaling pathways for laminin-5/α3β1 integrin-mediated cell survival had not been fully established. We report the unexpected finding of multiple interactions between 14-3-3 isoforms and proapoptotic proteins in the survival signaling pathway. Ln5-P4 motif within human laminin-5 α3 chain promotes cell survival and anti-apoptosis by inactivating Bad and YAP. This effect is achieved through the formation of 14-3-3ζ/p-Bad and 14-3-3σ/p-YAP complexes, which is initiated by α3β1 integrin and FAK/PI3K/Akt signaling. These complexes result in cytoplasmic sequestration of Bad and YAP and their subsequent inactivation. An increase in Akt1 activity in cells induces 14-3-3ζ and σ, p-Bad, and p-YAP, promoting cell survival, whereas decreasing Akt activity suppresses the same proteins and inhibits cell survival. Suppression of 14-3-3ζ with RNA-interference inhibits cell viability and promotes apoptosis. These results reveal a new mechanism of cell survival whereby the formation of 14-3-3ζ/p-Bad and 14-3-3σ/p-YAP complexes is initiated by laminin-5 stimulation via the α3β1 integrin and FAK/PI3K/Akt signaling pathways, thereby resulting in cell survival and anti-apoptosis.     

Molecular cloning and expression pattern of 14-3-3ζ from the malaria vector, Anopheles sinensis

14-3-3 proteins are known to play a pivotal role in cell survival, apoptosis and signal transduction. The 14-3-3ζ isoform has been cloned and characterized from many eukaryotic organisms, including the fruit fly and silkworm. However, no study on mosquito 14-3-3 has been reported to date. In an attempt to investigate the function of 14-3-3 in midgut epithelial cells undergoing apoptosis, a cDNA library was generated from the malaria vector, Anopheles sinensis , which was treated with apoptosis-inducing Actinomycin-D. We were able to identify and obtain A. sinensis 14-3-3ζ cDNA ( Ansi14-3-3ζ ) from expressed sequence tags (EST) analysis after conducting massive sequencing of the A. sinensis cDNA library. Ansi14-3-3ζ has very high homology to 14-3-3 homologs of various insects, such as Anopheles gambiae (100%), Aedes aegypti (100%), Drosophila melanogaster (96%), Bombyx mori (93%), Apis mellifera (93%) and Mus musculus (81%), indicating that mosquito 14-3-3ζ is a highly conserved gene in diverse organisms. Analysis of temporal expression patterns showed that Ansi14-3-3ζ mRNA is highly expressed in egg, early pupae and adult stages and is also expressed, although at low levels, in fourth instar larvae and late pupae. In response to two immune elicitors (lipopolysaccharide and laminarin), no striking induction of 14-3-3ζ mRNA was observed in A. sinensis . Further studies of the precise biological function, inducibility and subcellular distribution of 14-3-3ζ are required in Plasmodium invasion-induced apoptotic midgut cells in A. sinensis in the context of the Time Bomb model.     

Mutagenicity of bisphenol A and its suppression by interferon-α in human RSa cells

Bisphenol A is used as a monomer in the production of polycarbonate plastic products. The widespread use of bisphenol A has raised concerns about its effects in humans. Since there is little information on the mutagenic potential of the chemical, the mutagenicity of bisphenol A was tested using human RSa cells, which has been utilized for identification of novel mutagens. In genomic DNA from cells treated with bisphenol A at concentrations ranging from 1×10⁻⁷ to 1×10⁻⁵ M, base substitution mutations at K-ras codon 12 were detected using PCR and differential dot-blot hybridization with mutant probes. Mutations were also detected using the method of peptide nucleic acid (PNA)-mediated PCR clamping. The latter method enabled us to detect the mutation in bisphenol A-treated cells at a dose (1×10⁻⁸ M) equivalent to that typically found in the environment. Induction of ouabain-resistant (Oua^R) phenotypic mutation was also found in cells treated with 1×10⁻⁷ and 1×10⁻⁵ M of bisphenol A. The induction of K-ras codon 12 mutations and Oua^R mutations was suppressed by pretreating RSa cells with human interferon (HuIFN)-α prior to bisphenol A treatment. The cells treated with bisphenol A at the concentration of 1×10⁻⁶ M elicited unscheduled DNA synthesis (UDS). These findings suggested that bisphenol A has mutagenicity in RSa cells as well as mutagens that have been tested in these cells, and furthermore, that a combination of the PNA-mediated PCR clamping method with the human RSa cell line may be used as an assay system for screening the mutagenic chemicals at very low doses.     

ADAM22 plays an important role in cell adhesion and spreading with the assistance of 14-3-3

Cellular adhesion plays important roles in a variety of biological processes. The ADAM family contains disintegrin-like and metalloproteinase-like domains which potentially have cell adhesion and protease activities. Recent studies suggest that the interaction between 14-3-3zeta and ADAM22cyt can regulate cell adhesion and spreading, therefore it has a potential role in neural development and function. 14-3-3 family has seven highly conserved members that regulate various cellular functions. Using yeast two-hybrid method, we identified that ADAM22cyt bound some other 14-3-3 family members. The interaction was further confirmed by in vitro protein pull-down assay and co-immunoprecipitation. We also found that the overexpression of exogenous ADAM22 in HEK293 cells could significantly enhance cell adhesion and spreading, compared with the truncated ADAM22 lack of 14-3-3 binding motifs. These results strongly demonstrated a functional role for ADAM22/14-3-3 in cell adhesion and spreading.     

lncRNA NEAT1 facilitates melanoma cell proliferation,migration, and invasion via regulating miR-495-3p and E2F3

Melanoma contributes a lot to skin cancer-related deaths. lncRNAs are implicated in various diseases, including melanoma. lncRNA NEAT1 is frequently dysregulated and can play important roles in multiple cancers. Nevertheless, little has been studied about the function of NEAT1 in melanoma progression. In our present research, we displayed NEAT1 was overexpressed in melanoma cells. A series of functional assays showed that overexpression of NEAT1 promoted the proliferation, migration, and invasion of melanoma cells. By contrast, NEAT1 knockdown obviously restrained melanoma cell progression. Mechanistically, it was revealed that NEAT1 could directly bind with miR-495-3p, which led to a negative effect on miR-495-3p levels. In addition, miR-495-3p was significantly decreased in melanoma cells. Furthermore, E2F3 was postulated as the target of miR-495-3p and overexpression of this miR could suppress the levels of E2F3. Meanwhile, it was exhibited that melanoma cell proliferation, migration, and invasion induced by E2F3 silence was abrogated by miR-495-3p. Moreover, an in vivo xenograft nude mice model was established using A375 cells and it was indicated that NEAT1 promoted melanoma progression in vivo via regulating the miR-495-3p/E2F3 axis. In conclusion, we suggest that NEAT1 exerts an oncogenic effect on melanoma development via inhibition of miR-495-3p and induction of E2F3. NEAT1 might serve as a crucial prognostic biomarker of melanoma.     

Mammalian cell transformation and cell-mediated mutagenesis by carcinogenic polycyclic hydrocarbons.

The introduction of a polycyclic hydrocarbon such as benzo(alpha)pyrene (BP) into normal golden hamster embryo cell cultures results, in addition to cytotoxicity, in malignant cell transformation. Studies on the effect of different doses of BP on the normal cells showed that the frequency of transformed colonies was directly related to the dose of the carcinogen. Analysis of this dose-response curve suggests a one-event ("one-hit") response for transformation by this carcinogen. The one-event response for transformation by carcinogenic polycyclic hydrocarbons and the fact that these carcinogens bind to DNA in susceptible cells suggests that transformation can involve a single alteration in the genetic constitution of the treated cells. Carcinogens may, therefore, produce somatic mutations, some of which may involve the genes that control malignancy. Recently, considerable progress has been made in developing models for the study of chemical mutagenesis in mammalian cells. Using resistance to 8-azaguanine as a marker, positive correlations between mutagenicity and transformation were obtained with chemically reactive carcinogens such as N-acetoxy-N-2-fluorenyl-acetamide, N-methyl-N'-nitro-N-nitrosoguanidine and K-region epoxides of polycyclic hydrocarbons. However, no such correlations were obtained with the carcinogenic polycyclic hydrocarbons themselves, since the cell lines used in chemical mutagenesis do not metabolize these carcinogens. In order to obtain better correlations, we have developed a cell-mediated mutagenic assay with carcinogenic hydrocarbons in which Chinese hamster cells, which are susceptible for mutagenesis, were co-cultivated with lethally irradiated rodent cells that can metabolize these compounds. Using this cell mediated assay, we obtained mutagenesis with the carcinogenic hydrocarbons 7,12-dimethylbenz(alpha)anthracene (DMBA), BP, 3-methylcholanthrene and 7-methylbenz(alpha)anthracene; the most potent carcinogen, DMBA, gave the highest frequency of mutations. The polycyclic hydrocarbons, pyrene and benz(alpha)anthracene, which are not carcinogenic were also not mutagenic. We have therefore demonstrated a relationship between the carcinogenecity of polycyclic hydrocarbons and their mutagenicity in mammalian cells, without having to isolate their reative metabolic intermediates. It should be possible to use in this system human cells from different organs and individuals to screen for environmental chemicals hazardous to humans which have to be metabolically activated.     

The mutational spectrum of procarbazine in Drosophila melanogaster.

The antineoplastic agent Procarbazine was tested for the induction of genetic damage in Drosophila melanogaster. The compound was administered to adult males by oral application. The following types of genetic damage were measured: (1) sex-linked recessive lethals; (2) dominant lethals; (3) total and partial sex-chromosome loss; and (4) translocations. Procarbazine is highly mutagenic in causing recessive lethal mutations in all stages of spermatogenesis. In sperm a clear-cut concentration-effect relationship is not apparent, but in spermatids such a relationship is obtained for mutation induction at low levels of procarbazine exposure, while at high concentrations the induction of recessive lethals is not a function of concentration. A low induction of total sex-chromosome loss (X,Y) and dominant lethals was observed in metabolically active germ cells (spermatids), but procarbazine failed to produce well-defined breakage events, such as partial sex-chromosome loss (YL,YS) and II-III translocations. The results obtained in Drosophila melanogaster are discussed and compared with the mutational pattern reported in the mouse after procarbazine treatment.     

The C-terminus of Raf-1 acts as a 14-3-3-dependent activation switch

The Raf-1 protein kinase is a major activator of the ERK MAPK pathway, which links signaling by a variety of cell surface receptors to the regulation of cell proliferation, survival, differentiation and migration. Signaling by Raf-1 is regulated by a complex and poorly understood interplay between phosphorylation events and protein–protein interactions. One important mode of Raf-1 regulation involves the phosphorylation-dependent binding of 14-3-3 proteins. Here, we have examined the mechanism whereby the C-terminal 14-3-3 binding site of Raf-1, S621, controls the activation of MEK-ERK signaling. We show that phosphorylation of S621 turns over rapidly and is enriched in the activated pool of endogenous Raf-1. The phosphorylation on this site can be mediated by Raf-1 itself but also by other kinase(s). Mutations that prevent the binding of 14-3-3 proteins to S621 render Raf-1 inactive by specifically disrupting its capacity to bind to ATP, and not by gross conformational alteration as indicated by intact MEK binding. Phosphorylation of S621 correlates with the inhibition of Raf-1 catalytic activity in vitro, but 14-3-3 proteins can completely reverse this inhibition. Our findings suggest that 14-3-3 proteins function as critical cofactors in Raf-1 activation, which induce and maintain the protein in a state that is competent for both ATP binding and MEK phosphorylation.     

Killing and mutagenic actions of dacarbazine, a chemotherapeutic alkylating agent, on human and mouse cells: effects of Mgmt and Mlh1 mutations

Among various types of drugs designed for use in cancer chemotherapy, some have the potential for alkylation. After metabolic activation, these chemicals attack DNA and alkylate their bases, thereby preventing multiplication of rapidly growing tumor cells. Some of alkylated bases cause mutations, leading to untoward induction of tumors. To search for the rationale to separate lethal and mutagenic effects of alkylation drugs, we investigated actions of dacarbazine, a monofunctional triazene, on mouse and human cell lines defective in the Mgmt and/or the Mlh1 gene, the former encoding a DNA repair methyltransferase and the latter a protein involved in mismatch repair and induction of apoptosis. Mgmt-deficient cells are hypersensitive to the killing action of dacarbazine. On the other hand, cells defective in both Mgmt and Mlh1 genes are as resistant to the drug as are wild-type cells, in terms of survival, but do have many mutations after dacarbazine treatment. Thus, the killing and mutagenic actions of dacabazine can be dissociated by manipulating actions of these gene products.     

Cytogenetical characterisation of Chinese hamster 43-3B transferants with the amplified or non-amplified human DNA repair gene ERCC-1

A comparative study on the biological responses to different mutagens (UV, 4NQO, MMC, MMS and EMS) was made on CHO wild-type cells (CHO-9), its UV-hypersensitive mutant 43-3B, and 2 types of its transferants, i.e., one containing a few copies of the human repair gene ERCC-1 and the other having more than 100 copies of ERCC-1 (due to gene amplification). Cell survival, chromosomal aberrations and SCEs were used as biological end-points. The spontaneous frequency of chromosomal aberrations in the transferants was less than found in 43-3B mutant cells, but still 2-3 times higher than in wild-type CHO cells. The spontaneous frequency of SCEs in the transferants was less than in 43-3B and similar to that of wild-type cells. The induction of SCEs by all tested agents in transferants was similar to that found in CHO-9 cells, while the mutant is known to respond with higher frequencies. ERCC-1 also bestowed resistance to MMS and EMS on the mutant to induction of chromosomal aberrations and cell killing to levels comparable with those of the wild-type strain. On the other hand ERCC-1 could not completely regain the repair proficiency against cell killing and induction of chromosomal aberrations by UV or MMC to the wild-type level. These results suggest that the ERCC-1 corrects the repair defect in CHO mutant cells, but it is unable to rectify fully the defect; probable reasons for this are discussed. However, amplified transferants (having more than 100 copies of the ERCC-1 gene) restored the impaired repair function in 43-3B to UV-, MMC- or 4NQO-induced DNA damage better than non-amplified transferants with a few copies of the ERCC-1. This difference may be due to the high amount of gene product involved in the excision repair process in the amplified cells.     

Nuclear localization and interaction of RolB with plant 14-3-3 proteins correlates with induction of adventitious roots by the oncogene rolB

The rooting-locus gene B (rolB) on the T-DNA of the root-inducing (Ri) plasmid in Agrobacterium rhizogenes is responsible for the induction of transformed adventitious roots, although the root induction mechanism is unknown. We report here that the RolB protein of pRi1724 (1724RolB) is associated with Nicotianatabacum14-3-3-like protein omegaII (Nt14-3-3 omegaII) in tobacco bright yellow (BY)-2 cells. Nt14-3-3 omegaII directly interacts with 1724RolB protein. Green fluorescent protein (GFP)-fused 1724RolB is localized to the nucleus. GFP-fused mutant 1724RolB proteins having a deletion or amino acid substitution are unable to interact with Nt14-3-3 omegaII and also show impaired nuclear localization. Moreover, these 1724RolB mutants show decreased capacity for adventitious root induction. These results suggest that adventitious root induction by 1724RolB protein correlates with its interaction with Nt14-3-3 omegaII and the nuclear localization of 1724RolB protein.