Receptor-mediated activation of heterotrimeric guanine nucleotide-binding proteins (G proteins) results in the dissociation of alpha from beta gamma subunits, thereby allowing both to regulate effectors. Little is known about the regions of effectors required for recognition of G beta gamma. A peptide encoding residues 956 to 982 of adenylyl cyclase 2 specifically blocked G beta gamma stimulation of adenylyl cyclase 2, phospholipase C-beta 3, potassium channels, and beta-adrenergic receptor kinase as well as inhibition of calmodulin-stimulated adenylyl cyclases, but had no effect on interactions between G beta gamma and G alpha o. Substitutions in this peptide identified a functionally important motif, Gln-X-X-Glu-Arg, that is also conserved in regions of potassium channels and beta-adrenergic receptor kinases that participate in G beta gamma interactions. Thus, the region defined by residues 956 to 982 of adenylyl cyclase 2 may contain determinants important for receiving signals from G beta gamma.

The DREB transcription factors, which specifically interact with C-repeat/DRE (A/GCCGAC), play an important role in plant abiotic stress tolerance by controlling the expression of many cold or/and drought-inducible genes in an ABA-independent pathway. We have isolated three novel rice DREB genes, OsDREB1E, OsDREB1G, and OsDREB2B, which are homologous to Arabidopsis DREB genes. The yeast one-hybrid assay indicated that OsDREB1E, OsDREB1G, and OsDREB2B can specifically bind to the C-repeat/DRE element. To elucidate the function of respective OsDREB genes, we have stably introduced these to rice by Agrobacterium-mediated transformation. Transgenic rice plants analysis revealed that over-expression of OsDREB1G and OsDREB2B in rice significantly improved their tolerance to water deficit stress, while over-expression of OsDREB1E could only slightly improved the tolerance to water deficit stress, suggesting that the OsDREBs might participate in the stress response pathway in different manners.

BackgroundCD44 has been reported to be involved with tumor growth and metastasis and has also been implicated as a CSC marker in head and neck squamous cell cancer (HNSCC). However, the prognostic value of CD44 still remains controversial; hence, we investigated the correlation between CD44 and the clinicopathological features of HNSCC by meta-analysis.MethodsA comprehensive search was performed using PubMed, ISI web of Science and China National Knowledge Infrastructure (CNKI) up to April 2013. Only studies with immunohistochemical staining of HNSCC were considered. Data on TNM classification, tumor grade, disease free survival and 3- or 5-year overall survival rate were extracted.ResultsThirty studies with 2102 patients met the inclusion criteria for the meta-analysis. Fifteen studies used anti-pan-CD44 antibody, 9 used anti-CD44-v6 antibody, 2 used anti-CD44-v3 and 2 used anti-CD44s antibody, 1 used anti-CD44-v9, and 1 used anti-CD44-v6,-v3 and -v4-5 simultaneously. The total percentage of CD44 expression was 57.8%, with 49.3% in oral cancer patients, 66.4% in pharynx and 54.7% in larynx cancer patients expressing CD44. No significant correlation between clinical features and CD44 expression was revealed for oral cancer patients, but CD44 was shown to be associated with advanced T categories (larynx: RR = 1.33, 95% CI 1.01-1.76; larynx & pharynx RR = 1.21, 95% CI 1.08-1.35), worse N categories (larynx: RR = 2.53, 95% CI 1.99-3.21; larynx & pharynx RR = 1.95, 95% CI 1.35-2.82), higher tumor grades (larynx & pharynx RR = 1.71, 95% CI 1.04-2.79) and 5-year OS rates (larynx: RR = 0.62, 95% CI 0.47-0.83; larynx & pharynx RR = 0.66, 95% CI 0.47-0.94) in patients with laryngeal and pharyngolaryngeal cancer. In stratified analysis, pan-CD44 and CD44-v6 expression were both correlated with 5-year OS rate of patients with laryngeal (CD44: RR = 0.66, 95% CI 0.46-0.95; CD44-v6 RR = 0.53, 95% CI 0.37-0.77) and pharyngolaryngeal cancer (CD44: RR = 0.56, 95% CI 0.34-0.93; CD44-v6 RR = 0.53, 95% CI 0.37-0.77).ConclusionsOur analysis suggested that CD44 is related to worse T category, N category, tumor grade and prognosis, in pharyngeal and laryngeal cancer, but no clear association was revealed between CD44 expression and oral cancer.

ABSTRACTcDNA encoding a hormone-and guanine nu- Hormone-stimulated adenylyl cyclase [ATP pyrophosphatelyase (cyclizing), EC 4.6.1.1] is one of the best-studied guanine nucleotide-binding protein (G protein)-regulated signaling pathways. Detailed molecular information on the multiplicity of receptors and G proteins has been available for some time, but much less has been known about the effector until quite recently. Major progress was achieved with the development of affinity purification of adenylyl cyclase on forskolin-agarose (1) and the cloning of a calmodulinstimulated bovine brain adenylyl cyclase (2). This work has been followed by the recent cloning and characterization of three additional mammalian adenylyl cyclases (3-5). Hormone-regulated adenylyl cyclases have been functionally divided into two categories, calmodulin-sensitive and calmodulin-insensitive (6). Calmodulin-sensitive adenylyl cyclase activity is found predominantly in the brain, whereas liver and most other peripheral tissues contain only calmodulin-insensitive activity (6). We have had a long-standing interest in the glucagon-stimulated liver adenylyl cyclase system, and we set out to isolate the cDNA encoding the liver adenylyl cyclase. In this article we report on the isolation of cDNA clones encoding two distinct adenylyl cyclase enzymes that are highly related and widely expressed.* MATERIALS AND METHODSMaterials. Size-selected bovine cortex cDNA libraries in AZAP 11 (7), rat liver cDNA libraries in AZAP II (Stratagene) and in Agtll (Clonetech), and rat kidney libraries in AZAP II (Stratagene) and AgtlO (8) were used.Cloning. A 900-base-pair (bp) fragment encoding the final 300 amino acids of type 1 adenylyl cyclase (2) was amplified by PCR using specific primers from the published sequence, from 107 phage (9) of a >4.4-kilobase (kb) size-selected bovine cerebral cortex cDNA library in AZAP 11 (7). The product was subcloned in pBlueScript, sequenced, and used to screen a rat liver cDNA library in AZAP II by using standard methods (10). Positive inserts were recovered from the AZAP II vector by phagemid excision (11), and DNA sequences from double-stranded inserts in pBlueScript were determined by dideoxynucleotide chain-termination technique with specific oligonucleotide primers and T7 DNA polymerase (10). Ambiguous sequences were resequenced with 7-deaza-dGTP or dITP.Extreme 5' end clones were obtained by PCR screening of several rat liver and kidney cDNA libraries in various A phage vectors (9, 12). For each screening step, two nested antisense primers were prepared to known adenylyl cyclase sequences and used in sequential PCR reactions. In the first reactions, an aliquot of a cDNA library (107 phage) was amplified by using an antisense clone primer (21 bp) and one of a pair of primers that flank the virus multiple cloning site (i.e., T3 and T7 17-mer sequencing primers for AZAP II). Amplifications were performed for 35 cycles at 95TC for 1 min, 500C for 1 min, and 720C for 3 min. One microliter of the first reactions was used as ...

Regulation of basal activities of adenylyl cyclase (AC) 2 and 6, expressed in Sf9 cells by infection with recombinant baculovirus, was studied. An antipeptide antibody that recognizes AC2 and AC6 with equal sensitivity was used to establish that equivalent levels were expressed.

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BackgroundTumor hypoxia plays a fundamental role in resistance to therapy and disease progression. A number of studies have assessed the prognostic role of HIFs expression in head and neck cancer (HNC), but no consistent outcomes are reported.MethodologyA systematical search was performed to search relevant literatures in PubMed, Web of Science and ISI Web of Knowledge databases. The patients’ clinical characteristics and survival outcome were extracted. The correlation between HIFs expression and prognosis was analyzed.Principal FindingsA total of 28 studies assessed the association between HIFs and HNC survival, the result showed that overexpressed HIFs was significantly associated with increase of mortality risk (HR = 2.12; 95% CI: 1.52–2.94; I2 74%). Subgroup analysis on different HIF isoforms with OS indicated that both HIF-1α and HIF-2α were associated with worse prognosis. The pooled HRs were 1.72(95% CI 1.34–2.20; I2 70.7%) and 1.79(95% CI: 1.42–2.27, I2 0%). Further subgroup analysis was performed by different geographical locations, disease subtype, stage, types of variate analysis and cut-off value. The results revealed that overexpressed HIF-1α was significantly associated with poor prognosis in Asian patients (HR = 2.34; 95% CI: 1.76–3.1; I2 48.9%), but not in European patients (HR = 1.13; 95% CI: 0.77–1.66; I2 78.3%). Furthermore, HIF-1α overexpression was significantly associated with worse OS in oral carcinoma(HR = 2.1; 95% CI: 1.11–3.97; I2 81.7%), nasopharyngeal carcinoma(HR = 2.07; 95% CI:1.23–3.49; I2 22.5%) and oropharynx carcinoma(HR = 1.76; 95% CI:1.05–2.97; I2 61%), but not in laryngeal carcinoma(HR = 1.38; 95% CI: 0.87–2.19; I2 62.5%). We also found that the prognostic value of HIF-1α overexpression existed only when using staining and percentage as positive definition (HR = 1.82; 95% CI 1.42–2.33; I2 9.9%).ConclusionsThis study showed that overexpressed HIFs were significantly associated with increase of mortality risk. Subgroup analysis revealed that overexpressed HIF-1α was significantly associated with worse prognosis of HNC in Asian countries. Additionally, HIF-1α had different prognostic value in different HNC disease subtypes.