Biomedical subjects

Qi Wang

Publications and source records attributed to Qi Wang.

At least 109 records · Page 6Linked to original sources

PubMed2005

Effects of dihydropyridines and pyridines on multidrug resistance mediated by breast cancer resistance protein: in vitro and in vivo studies.

Breast cancer resistance protein (BCRP, ABCG2) is a recently identified member of the ATP-binding cassette family of cell surface transport proteins. This study was conducted to investigate the effect of a series of newly synthesized 1,4-dihydropyridines and pyridines, designed as potent P-glycoprotein inhibitors, on BCRP-mediated drug efflux both in vitro and in vivo. The effects of 25 synthesized dihydropyridines and corresponding pyridines along with 4 commercially available dihydropyridines (niguldipine, nicardipine, nifedipine, and nitrendipine) on the intracellular accumulation of the BCRP substrate mitoxantrone were evaluated in BCRP-expressing human breast cancer MCF-7/MX100 and human non-small cell lung cancer H460/MX20 cells. At a 2.5 microM concentration, 24 of 25 newly synthesized dihydropyridines and pyridines produced a significant increase of mitoxantrone accumulation in both cell lines. The most potent compound was able to enhance mitoxantrone accumulation approximately 4.5-fold, greater than that obtained with 10 microM fumitremorgin C, which is a specific BCRP inhibitor. The results from the two cell lines showed good correlation (r(2) = 0.71, p < 0.01). Niguldipine, nicardipine, and nitrendipine also demonstrated potent BCRP inhibition, whereas nifedipine had no effect. The effects of the dihydropyridine and pyridine compounds on mitoxantrone cytotoxicity paralleled their effects on mitoxantrone accumulation. Coadministration of a selected dihydropyridine compound, I(m) [DHP-014; 3-(3-(4,4-diphenylpiperidin-1-yl)propyl) 5-methyl 4-(3,4-dimethoxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate)] with topotecan, a good BCRP substrate and a moderate to poor P-glycoprotein substrate, resulted in significant increases in the systemic exposure and peak concentration of topotecan in Sprague-Dawley rats when oral topotecan (2 mg/kg) was combined with 20 mg/kg DHP-014. The observed increase of topotecan exposure provides proof-of-concept for in vivo inhibition of BCRP by these agents.

ATP Binding Cassette Transporter, Subfamily G, Mem↗

PubMed2005

Overexpression of Id-1 in prostate cancer cells promotes angiogenesis through the activation of vascular endothelial growth factor (VEGF).

Androgen-independent metastatic prostate cancer is the main cause of cancer related death in men. One of the reasons for this is the lack of understanding of the molecular mechanisms leading to the metastatic progression of prostate cancer. In this study, we have demonstrated that overexpression of Id-1 (inhibitor of differentiation/DNA synthesis), a member of the helix-loop-helix family proteins, is a key factor in promoting angiogenesis through activation of the vascular endothelial growth factor (VEGF) in prostate cancer cells. Using prostate cancer cells ectopically transfected with the Id-1 gene, we found that upregulation of Id-1 induced VEGF secretion through activation of the VEGF gene transcription. Downregulation of Id-1, however, led to the suppression of VEGF secretion and its gene promoter activity. The association between Id-1 and VEGF was also confirmed on human xenografts by immunohistochemical staining. In addition, the growth medium generated by the Id-1 expressing cells was able to promote morphological changes as well as capillary tube formation in human umbilical vein endothelial cells (HUVECs) at similar degrees to the recombinant human VEGF. Furthermore, inhibition of VEGF function by the treatment with an Flk-1 inhibitor, SU1498, or with the VEGF neutralizing antibody resulted in the reverse of the angiogenic effect on HUVECs. Our results suggest that overexpression of Id-1 in prostate cancer cells may provide an autocrine signal to promote angiogenesis through the activation of VEGF. Since increased Id-1 has been reported in many types of advanced human cancers, our results indicate that downregulation of Id-1 may be a novel target to inhibit the growth of metastatic cancers through the suppression of angiogenesis.

Adenocarcinoma↗

PubMed2005

[Effects of different means of fluid resuscitation on apoptosis of visceral organs in rats with hemorrhagic shock].

OBJECTIVE: To observe the effects of different means of fluid resuscitation on apoptosis of visceral organs in rats with hemorrhagic shock. METHODS: The tails of 8 male SD rats were cut to cause active bleeding. Blood was collected from the carotid arteries of another 24 male SD rats and heparinized, then the 24 rats were randomly divided into 3 equal groups: no fluid resuscitation group (NF group, carotid blood was collected as described above, the tail was cut and the blood from the tail was collected in container with heparin 30 min after, and hemostasis and heparin blood transfusion were performed 60 min after cutting of the tail), controlled fluid resuscitation group [NS40 group: isosmotic saline was infused during the period of 30 to 60 min after the tail cutting to maintain the mean arterial pressure (MAP) at about 40 mm Hg and then hemostasis and heparin blood transfusion were performed 60 min after cutting of the tail], and great quantity fluid rapid resuscitation group [NS80 group: a great quantity of isosmotic saline was infused during the period of 30 to 60 min after the tail cutting to maintain the MAP at about 80 mm Hg and then hemostasis and heparin blood transfusion were performed 60 min after cutting of the tail]. Blood specimens were collected at the time points 0, 120, and 150 min to undergo blood routine examination. Another blood specimens were collected at the time points 0, 30, 60, and 90 min to undergo lactic acid examination. The surviving rats were killed and their livers, kidneys, lungs, and small intestines were taken out to undergo pathology. Cell apoptosis was examined by flow cytometry and TUNEL. RESULTS: The survival rates of the NS40 and NS80 groups were significantly higher than that of the NF group (both P < 0.05). The blood lactic acid levels of the NS40 and NS80 groups at the time points 60 and 90 min were all significantly lower than those of the NF and control groups (all P < 0.05). Apoptosis in the liver, kidney, and small intestine mucosa of the NS80 group was significantly marked than in the NF and NS40 groups (all P < 0.01). CONCLUSION: Controlled fluid resuscitation obviously reduces the early death rate of rats with severe hemorrhagic shock and apoptosis in the liver, kidney, and small intestine mucosa thereof and may benefit the prognosis.

Animals↗

PubMed2005

The adsorption and localization of mixtures of C4-C7 alkane isomers in zeolites by computer simulation.

Grand canonical Monte Carlo and configurational-bias Monte Carlo techniques were employed to simulate the adsorption of binary mixtures of C(4)-C(7) alkane isomers in ISV and MOR zeolites at 300 K, and the results were compared to that in MFI. Unlike in MFI, the amount of adsorption of the linear and branched alkanes all increases with pressure increasing in ISV and MOR for 0.5-0.5 gas-phase mixtures. The location of alkane isomers is astatic, and it does not exhibit obvious orientation in ISV and MOR. The interaction energy of 2-methylpropane-zeolite is obviously higher than that of n-butane-zeolite in MFI. As to ISV and MOR, the interaction energy between 2-methylpropane and zeolite is a little lower than that between n-butane and zeolite. It can be found that the zeolite MFI behaves quite differently in adsorption from ISV and MOR.

Journal Article↗

PubMed2005

Size-controllable synthesis of monodispersed SnO2 nanoparticles and application in electrocatalysts.

Size-controllable tin oxide nanoparticles are prepared by heating ethylene glycol solutions containing SnCl(2) at atmospheric pressure. The particles were characterized by means of transmission electron microscopic (TEM), X-ray diffraction (XRD) studies. TEM micrographs show that the obtained material are spherical nanoparticles, the size and size distribution of which depends on the initial experimental conditions of pH value, reaction time, water concentration, and tin precursor concentration. The XRD pattern result shows that the obtained powder is SnO(2) with tetragonal crystalline structure. On the basis of UV/vis and FTIR characterization, the formation mechanism of SnO(2) nanoparticles is deduced. Moreover, the SnO(2) nanoparticles were employed to synthesize carbon-supported PtSnO(2) catalyst, and it exhibits surprisingly high promoting catalytic activity for ethanol electrooxidation.

Journal Article↗

PubMed2005

Ionic liquid and solid HF equivalent amine-poly(hydrogen fluoride) complexes effecting efficient environmentally friendly isobutane-isobutylene alkylation.

Isoparaffin-olefin alkylation was investigated using liquid as well as solid onium poly(hydrogen fluoride) catalysts. These new immobilized anhydrous HF catalysts contain varied amines and nitrogen-containing polymers as complexing agents. The liquid poly(hydrogen fluoride) complexes of amines are typical ionic liquids, which are convenient media and serve as HF equivalent catalysts with decreased volatility for isoparaffin-olefin alkylation. Polymeric solid amine:poly(hydrogen fluoride) complexes are excellent solid HF equivalents for similar alkylation acid catalysis. Isobutane-isobutylene or 2-butene alkylation gave excellent yields of high octane alkylates (up to RON = 94). Apart from their excellent catalytic performance, the new catalyst systems significantly reduce environmental hazards due to the low volatility of complexed HF. They represent a new, "green" class of catalyst systems for alkylation reactions, maintaining activity of HF while minimizing its environmental hazards.

Journal Article↗

PubMed2005

Further characterization of human DNA polymerase delta interacting protein 38.

Polymerase delta interacting protein 38 (PDIP38) was identified as a human DNA polymerase (pol) delta interacting protein through a direct interaction with p50, the small subunit of human pol delta. PDIP38 was also found to interact with proliferating cell nuclear antigen, which suggested that it might play a role in vivo in the processes of DNA replication and DNA repair in the nucleus. In order to characterize further this novel protein, we have examined its subcellular localization by the use of immunochemical and cellular fractionation techniques. These studies show that PDIP38 is a novel mitochondrial protein and is localized mainly to the mitochondria. PDIP38 was shown to possess a functional mitochondrial targeting sequence that is located within the first 35 N-terminal amino acid residues. The mature PDIP38 protein is about 50 amino acid residues smaller than the full-length precursor PDIP38 protein, consistent with it being processed by cleavage of the mitochondrial targeting sequence during entry into the mitochondria. His-tagged mature PDIP38 inhibited pol delta activity in vitro and interacted with human papillomavirus 16 E7 oncoprotein, suggesting that PDIP38 might play a role in the pol delta-mediated viral DNA replication. Although the localization of PDIP38 to the mitochondria suggests that it serves functions within the mitochondria, we cannot eliminate the possibility that it may be involved in pol delta-mediated DNA replication or DNA repair under certain conditions such as viral infection.

Cell Line↗

PubMed2005

Towards precise classification of cancers based on robust gene functional expression profiles.

BACKGROUND: Development of robust and efficient methods for analyzing and interpreting high dimension gene expression profiles continues to be a focus in computational biology. The accumulated experiment evidence supports the assumption that genes express and perform their functions in modular fashions in cells. Therefore, there is an open space for development of the timely and relevant computational algorithms that use robust functional expression profiles towards precise classification of complex human diseases at the modular level. RESULTS: Inspired by the insight that genes act as a module to carry out a highly integrated cellular function, we thus define a low dimension functional expression profile for data reduction. After annotating each individual gene to functional categories defined in a proper gene function classification system such as Gene Ontology applied in this study, we identify those functional categories enriched with differentially expressed genes. For each functional category or functional module, we compute a summary measure (s) for the raw expression values of the annotated genes to capture the overall activity level of the module. In this way, we can treat the gene expressions within a functional module as an integrative data point to replace the multiple values of individual genes. We compare the classification performance of decision trees based on functional expression profiles with the conventional gene expression profiles using four publicly available datasets, which indicates that precise classification of tumour types and improved interpretation can be achieved with the reduced functional expression profiles. CONCLUSION: This modular approach is demonstrated to be a powerful alternative approach to analyzing high dimension microarray data and is robust to high measurement noise and intrinsic biological variance inherent in microarray data. Furthermore, efficient integration with current biological knowledge has facilitated the interpretation of the underlying molecular mechanisms for complex human diseases at the modular level.

Algorithms↗

PubMed2005

Sequence diversity of T-superfamily conotoxins from Conus marmoreus.

Remarkable sequence diversity of T-superfamily conotoxins was found in a mollusk-hunting cone snail Conus marmoreus. The sequence of mr5a purified from the snail venom was determined, while six other sequences of Mr5.1a, Mr5.1b, Mr5.2, Mr5.3, Mr5.4a, and Mr5.4b were deduced from their corresponding cDNA cloned by RACE approach. mr5a of 10 amino acid residues is one of the shortest T-superfamily conotoxins ever found. They all share a typical (-CC-CC-) Cys pattern, a conserved signal peptide and a long 3'-untranslated region. A consensus Glu residue is preceded by the second two adjacent cysteines in all these toxins except in mr5a, whereas Mr5.1a, Mr5.1b, Mr5.4a and Mr5.4b are abundant in Trp residues. The identification of these highly divergent T-superfamily conotoxins will facilitate the understanding the relationship of their structure and function.

Amino Acid Sequence↗

PubMed2005

Self-assembled silane monolayers: fabrication with nanoscale uniformity.

Illustrating direct connections between surface chemical events and mechanical and topological characteristics of self-assembled monolayers derived from octadecyltrichlorosilane (OTS) adsorption on Si(100), layers prepared in the presence and absence of moisture have been characterized. Uniform and robust self-assembled monolayers are demonstrated provided the Si(100) surface is fully hydroxylated by treatment in piranha solution and the dried surface is exposed to OTS under strict anhydrous conditions. With nanoscale resolution, the uniform mechanical properties are confirmed by interfacial force microscopy while the uniform topological properties are evident in atomic force microscopy images. The monolayer character of the OTS coverage is confirmed by X-ray photoelectron spectroscopy, ellipsometry, and patterning experiments. Analogous surfaces, prepared in the presence of moisture, exhibit nonuniform topological and mechanical properties.

Journal Article↗

PubMed2005

Renal clearance of gamma-hydroxybutyric acid in rats: increasing renal elimination as a detoxification strategy.

Intoxication with gamma-hydroxybutyric acid (GHB) is associated with coma, seizure, and death; treatment of overdoses is symptomatic. The objectives of this investigation were to characterize the renal clearance and total clearance of GHB in rats and to evaluate potential strategies for increasing the elimination of GHB after drug overdoses. GHB was administered by i.v. infusion at low (108 mg/h/kg), medium (128 mg/h/kg), or high (208 mg/h/kg) doses. Crossover studies were performed under steady-state conditions using the medium dose in the absence or presence of l-lactate, pyruvate, d-mannitol, sodium bicarbonate, or normal saline. GHB in plasma and urine samples was assayed using liquid chromatography-tandem mass spectrometry. Infusion of the low, medium, and high doses of GHB produced steady-state plasma concentrations of 0.22 +/- 0.04, 0.43 +/- 0.05, and 0.68 +/- 0.11 mg/ml. The renal clearance of the medium (51.8 +/- 13.0 ml/h/kg) and high (97.1 +/- 43.1 ml/h/kg) doses was significantly higher than that of the low dose (14.9 +/- 5.1 ml/h/kg), whereas the total clearance values were significantly lower than that of the low dose. The renal clearance was significantly increased by the concomitant administration of l-lactate, pyruvate, d-mannitol, or sodium bicarbonate with GHB but was not altered by normal saline. The total and metabolic clearance values were significantly increased by all treatments except normal saline. Overall, our results indicated that the renal clearance of GHB is dose-dependent, involving capacity-limited reabsorption. Monocarboxylate transport inhibitors, osmotic diuresis using d-mannitol, or the administration of sodium bicarbonate can increase the renal and total clearances of GHB. The approaches used in this investigation may offer potential detoxification strategies for the treatment of GHB overdoses.

Animals↗

PubMed2005

[Screening for the G1528C mutation in long chain fatty acid oxidation enzyme in Han nationality in Beijing population].

OBJECTIVE: To explore the carrier rate of G1528C mutation in alpha-subunit gene of MTP in Chinese newborns. METHODS: 1 200 cases of cord blood samples were taken in pregnant women with Han nationality in Chinese. PCR-RFLP analysis was conducted for detection of G1528C mutation. RESULTS: No. G1528C mutations in LCHAD gene were found in these study subjects. CONCLUSION: G1528C is probably not the common prevalent mutation in MTP gene in Chinese. Different prevalent mutation between Chinese and Western white people needs further study.

China↗

PubMed2005

Mitotic arrest deficient 2 expression induces chemosensitization to a DNA-damaging agent, cisplatin, in nasopharyngeal carcinoma cells.

Recently, mitotic arrest deficient 2 (MAD2)-mediated spindle checkpoint is shown to induce mitotic arrest in response to DNA damage, indicating overlapping roles of the spindle checkpoint and DNA damage checkpoint. In this study, we investigated if MAD2 played a part in cellular sensitivity to DNA-damaging agents, especially cisplatin, and whether it was regulated through mitotic checkpoint. Using nine nasopharyngeal carcinoma (NPC) cell lines, we found that decreased MAD2 expression was correlated with cellular resistance to cisplatin compared with the cell lines with high levels of MAD2. Exogenous MAD2 expression in NPC cells also conferred sensitivity to DNA-damaging agents especially cisplatin but not other anticancer drugs with different mechanisms of action. The increased cisplatin sensitivity in MAD2 transfectants was associated with mitotic arrest and activation of apoptosis pathway evidenced by the increased mitotic index and apoptosis rate as well as decreased Bcl-2 and Bax ratio and expression of cleaved poly(ADP-ribose) polymerase and caspase 3. Our results indicate that the MAD2-induced chemosensitization to cisplatin in NPC cells is mediated through the induction of mitotic arrest, which in turn activates the apoptosis pathway. Our evidence further confirms the previous hypothesis that spindle checkpoint plays an important part in DNA damage-induced cell cycle arrest and suggests a novel role of MAD2 in cellular sensitivity to cisplatin.

Antineoplastic Agents↗

PubMed2005

A diffusion model for the fluids confined in micropores.

The self-diffusion coefficients were calculated by molecular dynamics simulations and the effects of pore width, temperature, and fluid density on diffusion behavior of simple fluid argon and polar fluid water confined in micropores were analyzed and studied. A mathematical model describing diffusion behavior of fluids confined in micropores was proposed from the theories of molecular dynamics and molecular kinematics, and validated on the basis of the simulation results at various conditions. The model indicates that the diffusion coefficient is proportional to the square root of the pore width and to the temperature divided by the density squared. It is applicable to either liquid or gas states and only two parameters are required.

Journal Article↗

PubMed2005

Association between endogenous gene expression and growth regulation induced by TGF-beta1 in human gastric cancer cells.

AIM: To investigate the association between endogenous gene expression and growth regulation including proliferation and apoptosis induced by transforming growth factor-beta1 (TGF-beta1) in human gastric cancer (GC) cells. METHODS: Reverse transcription polymerase chain reaction (RT-PCR) was performed to detect the main components of the TGF-beta1/Smads signal pathway in human poorly differentiated GC cell line BGC-823. Localization of Smad proteins was also determined using immunofluorescence. Then, the BGC-823 cells were cultured in the presence or absence of TGF-beta1 (10 ng/mL) for 24 and 48 h, and the effects of TGF-beta1 on proliferation and apoptosis were measured by cell growth curve and flow cytometry (FCM) analysis. The ultrastructural features of BGC-823 cells with or without TGF-beta1 treatment were observed under transmission electron microscope. The apoptotic cells were visualized by means of the terminal deoxynucleotidyl transferase (TdT)-mediated dTUP in situ nick end-labeling (TUNEL) method. Meanwhile, the expression levels of endogenous p15, p21 and Smad7 mRNA and the corresponding proteins in the cells were detected at 1, 2 and 3 h after culture in the presence or absence of TGF-beta1 (10 ng/mL) by semi-quantitative RT-PCR and Western blot, respectively. RESULTS: The TGF-beta1/Smad signaling was found to be intact and functional in BGC-823 cells. The growth curve revealed the most evident inhibition of cell proliferation by TGF-beta1 at 48 h, and FCM assay showed G1 arrest accompanied with apoptosis induced by TGF-beta1. The typical morphological changes of apoptosis were observed in cells exposed to TGF-beta1. The apoptosis index (AI) in TGF-beta1-treated cells was significantly higher than that in the untreated controls (10.7+/-1.3% vs 0.32+/-0.06%, P<0.01). The levels of p15, p21 and Smad7 mRNA and corresponding proteins in cells were significantly up-regulated at 1 h, but gradually returned to basal levels at 3 h following TGF-beta1 (10 ng/mL) treatment. CONCLUSION: TGF-beta1 affects both proliferation and apoptosis of GC cells through the regulation of p15 and p21, and induces transient expression of Smad 7 as a negative feedback modulation of TGF-beta1 signal. Our results suggest a novel functional role of p21 as an accelerant of TGF-beta1-mediated apoptosis in GC cells.

Adenocarcinoma↗

PubMed2005

Epigenetic inactivation of CHFR in nasopharyngeal carcinoma through promoter methylation.

Chromosomal instability (CIN) is a cytogenetic hallmark of human cancers. Increasing evidence suggests that impairment of mitotic checkpoint is causally associated with CIN. CHFR is one of the mitotic checkpoint regulators and it delays chromosome condensation in response to mitotic stress. Epigenetic inactivation of CHFR through promoter CpG hypermethylation may lead to CIN and has been reported in several human cancers. In this study, we investigated the CHFR gene expression in a panel of nasopharyngeal carcinoma (NPC), prostate, ovarian, and breast cancer cell lines. We found that the expression of CHFR mRNA was significantly decreased or undetectable in all eight NPC cell lines as well as three human NPC xenografts, whereas non-malignant nasopharyngeal cell lines and other cancer cell lines tested expressed CHFR at relatively high levels. Hypermethylation of CHFR promoter region was also strongly correlated with decreased CHFR expression in NPC cell lines and xenografts. Treatment with a methyltransferase inhibitor, 5-aza-2'-deoxycytidine, led to restoration of CHFR expression in NPC cell lines. More importantly, hypermethylation of CHFR promoter region was detected in 61.1% (22 out of 36) of primary NPC tumors while it was absent in non-malignant tissues. These findings suggest that downregulation of CHFR is a common event in NPC cells which may be due to hypermethylation of the gene promoter region.

Cell Cycle Proteins↗

PubMed2005

Stable expression of EBERs in immortalized nasopharyngeal epithelial cells confers resistance to apoptotic stress.

Epstein-Barr virus (EBV) infection is closely associated with the development of nasopharyngeal carcinoma (NPC). The EBV-encoded RNAs (EBERs) are the most abundant EBV transcripts (about 10(7) copies per cell) in EBV infected cells. However, the cellular function of EBER expression, particularly in nasopharyngeal epithelial cells, remains poorly understood. EBERs acquire secondary structures analogous to double-stranded RNA (dsRNA) and may bind to the double-stranded RNA-dependent protein kinase (PKR) and interfere with its function. Activation of PKR involves autophosphorylation resulting in protein synthesis inhibition and cellular apoptosis. Induction of cellular apoptosis by activation of PKR may be an antiviral response adopted by virally infected cells. We have examined the functional properties of EBER expression in an immortalized nasopharyngeal epithelial cell line (NP69). Expression of EBERs was achieved by transfecting the NP69 cells with an EBER-expressing plasmid, pESK10. The EBER-expressing NP69 cells attained a higher growth rate compared to cells transfected with control plasmid (pcDNA3). However, the EBER-expressing NP69 cells did not form colonies in soft agar and were non-tumorigenic in nude mice. To investigate if EBERs may protect the nasopharyngeal epithelial cells from apoptotic insults, we treated the EBER-expressing NP69 cells with a dsRNA analogue, poly(I).poly(C) (pIC), to activate PKR in cells and examined for their responses. Lower level of PKR phosphorylation and elevation of Bcl-2 were observed in EBER-expressing NP69 cells. In addition, other apoptotic markers including the cleaved forms of caspase-3 and poly(ADP)ribose polymerase (PARP) were found to be lower in EBER-expressing NP69 cells after treatment with pIC. Lower phosphorylation levels of p38 MAPK (mitogen-activated protein kinase) and c-jun were also observed in EBER-expressing NP cells. Our results suggest that EBER expression may confer an apoptotic-resistant phenotype in immortalized nasopharyngeal epithelial cells.

Animals↗

PubMed2005

Cloning and biochemical properties of CDPK gene OsCDPK14 from rice.

A rice CDPK gene, OsCDPK14 (AY144497), was cloned from developing caryopses of rice (Oryza sativa cv. Zhonghua 15). Its cDNA sequence (1922 bp) contains an ORF encoding a 514 amino acids protein (56.7kD, pl 5.18). OsCDPK14 shows the typical structural features of the CDPK family, including a conserved catalytic Ser/Thr kinase domain, an autoinhibitory domain and a CaM-like domain with four putative Ca2+-binding EF hands. Subcellular targeting indicated that OsCDPK14 was located in the cytoplasm, probably due to the absence of myristoylation and palmitoylation motifs. OsCDPK14 was expressed in Escherichia coli and purified from bacterial extracts. The recombinant protein was shown to be a functional protein kinase using Syntide-2, a synthetic peptide. Kinase activity was shown to be Ca2+-dependent, and this activation was strongly enhanced by Mn2+ and inhibited by W7 in vitro. These results provide significant insights into the regulation and biochemical properties of OsCDPK14, suggesting OsCDPK14 may be a signal factor of cytoplasm in rice plant.

Amino Acid Sequence↗