Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.11.1 (protein kinase)
 81,284 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vasostatin, a fragment of calreticulin, was transfected in the BON cell line to evaluate the feasibility of using it for gene therapy in neuroendocrine tumors. Vasostatin transfected cells were subcutaneously inoculated in nude mice. Burkitt lymphoma cell line, CA46, colorectal adenocarcinoma cell line, SW480, as well as endothelial cells PAE and SVEC4 were used for evaluating the function of vasostatin. The results demonstrated that vasostatin transfer caused enhanced malignant behavior of neuroendocrine tumor cell line, BON. Cell adhesion, spreading and cellular invasion were also enhanced in vasostatin-expressing BON cells. Tumor suppressor genes including p53, nm23, Rb and vinculin were down-regulated. Moreover, cell cycle regulatory protein, p27kip1, and cell differentiation-related protein kinase, PKR, were also significantly down-regulated. Furthermore, expression of NKG2D ligands, MICA and MICB, were down-regulated. Mice implanted with vasostatin-expressing BON cells showed an earlier and faster tumor growth compared to wild type. Anti-proliferative effects of vasostatin could not be proven in other cells except in PAE. These results indicated that vasostatin does probably not have a tumor growth inhibitory effect by itself, but rather modulates processes which are necessary for tumor growth. Therefore, one should be very careful when using vasostatin as an anti-tumoral agent in clinical trials, at least for neuroendocrine tumors.
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PMID:Gene transfer of vasostatin, a calreticulin fragment, into neuroendocrine tumor cells results in enhanced malignant behavior. 1629 70

Cystic fibrosis (CF) results from mutations within the cystic fibrosis transmembrane-conductance regulator (CFTR) protein. The AMP-activated protein kinase (AMPK) is a heterotrimer composed of different isoforms of the alphabetagamma subunits, where the alpha1 catalytic subunit binds CFTR. Nucleoside diphosphate kinase (NDPK, NM23/awd) converts nucleoside diphosphates to nucleoside triphosphates but also acts as a protein kinase. We recently showed that AMPK alpha1 binds NDPK-A in lung epithelial cytosol. Here we report that in the plasma membrane of human airway epithelial cells, NDPK-A and AMPK alpha1 associate with the plasma membrane via CFTR. We show that the regulatory domain of CFTR binds NDPK-A whereas AMPK gamma1 or gamma2 bind the first nucleotide binding domain (NBD1) and AMPK alpha1 binds the second (NBD2) of CFTR. We also show that NDPK-A specifically binds AMPK alpha1 and AMPK gamma2 subunits, thereby specifying the isozyme of AMPK heterotrimer that associates with CFTR at the membrane. Thus, the combined data provide novel insight into the subunit composition of the epithelial CFTR/AMPK/NDPK complex, such that: CFTR interacts specifically with AMPK alpha1, gamma2 and NDPK-A and not NDPK-B or AMPK gamma1.
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PMID:NDPK-A (but not NDPK-B) and AMPK alpha1 (but not AMPK alpha2) bind the cystic fibrosis transmembrane conductance regulator in epithelial cell membranes. 1646 5

Nm23 was the first metastasis suppressor gene identified. This gene encodes a NDP kinase that also exhibits other properties like histidine protein kinase and interactions with proteins and DNA. The S120G mutant of NDPK-A has been identified in aggressive neuroblastomas and has been found to reduce the metastasis suppressor effect of Nm23. In order to understand the differences between the wild type and the S120G mutant, we have determined the structure of both mutant and wild type NDPK-A in complex with ADP. Our results reveal that there are no significant changes between the two enzyme versions even in the surroundings of the catalytic histidine that is required for NDP kinase activity. This suggests that the S120G mutation may affect an other protein property than NDP kinase activity.
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PMID:Crystal structures of S120G mutant and wild type of human nucleoside diphosphate kinase A in complex with ADP. 1694 99

Previously we elucidated the molecular interaction between the nucleoside diphosphate kinase A (NDPK-A)/AMP-activated protein kinase (AMPK) alpha1 complex, discovering a process we termed "substrate channeling." Here, we investigate the protein-protein interaction of the substrate channeling complex with the pleiotropic protein kinase, CK2 (formerly casein kinase 2). We show that CK2 is part of the NDPK-A/AMPK alpha1 complex under basal (background AMPK activity) conditions, binding directly to each of the complex components independently. We report that when S122 on NDPK-A is phosphorylated by AMPK alpha1 in vivo, (i.e., stimulation of AMPK using either metformin or phenformin) initiating the substrate channeling mechanism, the catalytic subunit of CK2 (CK2alpha) is expelled from the complex and translocates to bind NDPK-B, a closely related but independent isoform of NDPK. Thus, we find that the AMPK-dependent phospho-status of S122 on NDPK-A determines whether CK2alpha swaps partners between NDPK-A and NDPK-B. This is the first reported linkage between NDPK-A and NDPK-B via a phosphorylation pathway and could explain the complex biology of NDPK. This study also offers an explanation as to how CK2alpha exclusion mutations (S120A or S122D of NDPK-A) on NDPK-A might have implications in cancer biology and general cellular energy metabolism.
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PMID:Protein kinase CK2 acts as a signal molecule switching between the NDPK-A/AMPK alpha1 complex and NDPK-B. 1790 30

The Nm23-H1 gene is a metastasis suppressor gene. However, its biochemical mechanism of suppressing the metastatic potential of cancer cells is still unknown. The previous hypothesis that a histidine protein kinase activity may contributes to the motility-suppressive effect of Nm23-H1 could not explain why the H118F mutant, a kinase-deficient mutant, still had motility-suppressive ability. We conducted a study on the double mutant P96S/S120G of Nm23-H1 and succeeded in introducing the RP-HPLC method in NDPK assay. The results showed that the double mutant P96S/S120G, when expressed in the bacteria, was completely aggregated in inclusion bodies; this mutant abrogated not only its motility-suppressive ability, but also its NDPK activity. Based on previous work and this study, we prompted that the deficiency of motility-suppressive function of S120G, P96S, and P96S/S120G mutants was due to their altered structure, which might deprive Nm23-H1 of most activities including kinase activity or interactions with other proteins.
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PMID:Double mutant P96S/S120G of Nm23-H1 abrogates its NDPK activity and motility-suppressive ability. 1733 72

Nucleoside diphosphate kinase A (NDPK-A) regulates the alpha1 isoform of the AMP-activated protein kinase (AMPK alpha1) selectively, independent of [AMP] and surrounding [ATP], by a process termed substrate channelling. Here, we show, using a range of empirically validated biochemical techniques, that the muscle form (M-LDH or LDH-A) and the heart form (H-LDH or LDH-B) of lactate dehydrogenase are physically associated with the liver cytosolic substrate-channelling complex such that M-LDH associates with NDPK-A, AMPK alpha1 and casein kinase 2 (CK2), whereas H-LDH associates with local NDPK-B. We find that the species of LDH bound to the substrate-channelling complex regulates the in vivo enzymatic activities of both AMPK and CK2, and has a downstream effect on the phospho-status of acetyl CoA carboxylase, a key regulator of cellular fat metabolism known to be a part of the cytosolic substrate-channelling complex in vivo. We hypothesise that the regulatory presence of LDH in the complex couples the substrate-channelling mechanism to both the glycolytic and redox states of the cell, allowing for efficient sensing of cell metabolic status, interfacing with the substrate-channelling complex and regulating the enzymatic activities of AMPK and CK2, two critical protein kinases.
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PMID:M-LDH serves as a regulatory subunit of the cytosolic substrate-channelling complex in vivo. 1757 40

The combination of an increase in the cAMP-phosphodiesterase activity of h-prune and its interaction with nm23-H1 have been shown to be key steps in the induction of cellular motility in breast cancer cells. Here we present the molecular mechanisms of this interaction. The region of the nm23-h-prune interaction lies between S120 and S125 of nm23, where missense mutants show impaired binding; this region has been highly conserved throughout evolution, and can undergo serine phosphorylation by casein kinase I. Thus, the casein kinase I delta-epsilon specific inhibitor IC261 impairs the formation of the nm23-h-prune complex, which translates 'in vitro' into inhibition of cellular motility in a breast cancer cellular model. A competitive permeable peptide containing the region for phosphorylation by casein kinase I impairs cellular motility to the same extent as IC261. The identification of these two modes of inhibition of formation of the nm23-H1-h-prune protein complex pave the way toward new challenges, including translational studies using IC261 or this competitive peptide 'in vivo' to inhibit cellular motility induced by nm23-H1-h-prune complex formation during progression of breast cancer.
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PMID:Phosphorylation of nm23-H1 by CKI induces its complex formation with h-prune and promotes cell motility. 1790 97

Metastasis of cancer cells from the primary tumor is associated with poor prognosis and decreased overall survival. One protein implicated in inhibiting metastasis is the tumor metastasis suppressor nonmetastatic protein 23 homologue 1 (NM23-H1). NM23-H1 is a multifunctional protein, which, in addition to limiting metastasis, has DNase and histidine protein kinase activities. We have identified new functions for NM23-H1 in influencing estrogen receptor alpha (ER alpha)-mediated gene expression. Using a battery of molecular and biochemical techniques, we show that NM23-H1 interacts with ER alpha and increases the ER alpha-estrogen response element (ERE) interaction. When NM23-H1 expression is increased in U2 osteosarcoma and MDA-MB-231 breast cancer cells, transcription of a transiently transfected, estrogen-responsive reporter plasmid is decreased. More importantly, when endogenous NM23-H1 expression is knocked down in MCF-7 human breast cancer cells using small interfering RNA, estrogen responsiveness of the progesterone receptor (PR), Bcl-2, cathepsin D, and cyclin D1 genes, but not the pS2 gene, is enhanced. Furthermore, NM23-H1 associates with the region of the PR gene containing the +90 activator protein 1 site, but not with the ERE-containing region of the pS2 gene, indicating that NM23-H1 mediates gene-specific effects by association with endogenous chromatin. Our studies suggest that the capacity of NM23-H1 to limit the expression of estrogen-responsive genes such as cathepsin D and Bcl-2, which are involved in cell migration, apoptosis, and angiogenesis, may help to explain the metastasis-suppressive effects of this protein. The complementary abilities of ER alpha and NM23-H1 together to influence gene expression, cell migration, and apoptosis could be key factors in helping to determine tumor cell fate.
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PMID:Interaction of the tumor metastasis suppressor nonmetastatic protein 23 homologue H1 and estrogen receptor alpha alters estrogen-responsive gene expression. 1797 5

To investigate genes involved in cancer metastasis, mRNA differential display was used to compare the levels of gene expression of two cancer sublines derived from prostate carcinoma cell PC-3M that had different metastatic potentials. The differentially expressed genes were confirmed by Northern blot, and sequenced. The fulllength cDNA of a tumor metastasis suppressor gene (TMSG-1) was obtained by using EST assembling and verified by RT-PCR and sequencing. The results showed that expression levels of TMSG-1 were lower in the highly metastatic cell line 1E8, compared with the nonmetastatic cell line 2B4. The difference was significant. Fulllength cDNA of TMSG-1 was about 2 kb, containing an open reading frame that encoded a protein of 230 amino acids. GenBank Blastn showed no marked homology with known genes. The functional prediction of amino acids sequence encoded by TMSG-1 gene indicated TMSG-1 protein was transmembrane protein, with 3 transmembrane domains, 3 putative protein kinase phosphorylation sites, 2 casein kinase II phosphorylation sites and 1 Nmyristoylation site. The pattern of TMSG1 expression in 6 types of human tumor tissues indicated levels of transcripts were the highest in prostate carcinoma. TMSG-1 had lower expression in metastases of lung carcinoma compared to primary lung carcinoma. Similarly the expression levels were higher in welldifferentiated colon carcinoma than that in poorly differentiated colon carcinoma. TMSG-1 could also be detected in breast, ovarian, and pancreatic carcinoma. In 9 samples of primary gastric carcinoma tissues, RT-PCR and densitometric analysis demonstrated TMSG-1 expression levels in samples with lymph node metastases had a decreased tendency, compared to those without lymph node metastases. The difference was significant by student's t test (P< 0.05). These results indicated TMSG-1 expression levels were inversely correlated with tumor metastatic potential.
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PMID:Identification of tumor metastasisrelated gene TMSG-1 by mRNA differential display. 1875 44

The NM23 family proteins are involved in a variety of biological processes including tumor metastasis, development, and differentiation; however, their functions in the regulation of cellular proliferation are poorly understood. We have investigated the role of one NM23 family protein, NM23H2, in the regulation of cellular proliferation directed by the extracellular signal regulated kinase (ERK) pathway. The activity of ERKs was enhanced by knockdown of endogenous NM23H2 and blocked by overexpression of NM23H2 in both NIH3T3 and HEK293 cells. Additionally, the epidermal growth factor (EGF)- and oncogenic Ras(G12R)-induced proliferation of both HEK293 and NIH3T3 cells was reduced by NM23H2 overexpression. Furthermore, activation of Raf-1, MEK and the ERKs by either EGF or Ras(G12R) was inhibited by NM23H2 overexpression. Together, our data indicate that NM23H2 is a negative regulator of cellular proliferation stimulated by EGF- and Ras-mediated activation of the ERK pathway.
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PMID:NM23H2 inhibits EGF- and Ras-induced proliferation of NIH3T3 cells by blocking the ERK pathway. 1902 60


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