Objective： To investigate the expressions and correlations of Pin1, β-catenin and cyclin D1 in elderly lung carcinomas. Methods： The expressions of Pin1, β-catenin and cyclin D1 were examined in the specimens of 9...Objective： To investigate the expressions and correlations of Pin1, β-catenin and cyclin D1 in elderly lung carcinomas. Methods： The expressions of Pin1, β-catenin and cyclin D1 were examined in the specimens of 92 elderly lung carcinomas and 10 normal lung tissues by immunohistochemistry and explored the relationship between the expression levels and clinicopathological factors. Results： （1） The overexpression of Pin1 and cyclin D1 in lung carcinomas was 46 （50%） cases and 60 （65.22%） cases respectively and 56 （60.82%） cases showed positive immunoreactivity for 13-catenin in the nuclear and （or） cytoplasmic fraction in tumor tissues. In normal tissue, the expressions of Pin1 and cyclin D1 were negative, the expression of β-catenin was lied in cell membrane. （2） In lung carcinomas the expressions of Pin1, β-catenin and cyclin D1 correlated with tumor differentiation （P 〈 0.05）. The pesitive expression rate and intensity of Pin1 correlated with tumor stage （P = 0.032） and lymph node positive disease （P = 0.041）. The expression of β-catenin correlated with lymph node positive disease （P = 0.012）. （3） High expression levels of Pin1 correlated with aberrant I]-catenin expression （P = 0.000） but did not show a correlation with cyclin D1 （P = 0.157）. Conclusion： In elderly lung carcinomas, the positive expression of Pin1 causes abnormal accumulation of β-catenin and actives its target gene, however, this target gene was not cyclin DI. The detection of Pin1 expression had some clinical significance in estimating prognosis of elderly patient with lung carcinomas.展开更多
Being sessile organisms, plants evolved an unparalleled plasticity in their post-embryonic development, allowing them to adapt and fine-tune their vital parameters to an ever-changing environment. Cross-talk between p...Being sessile organisms, plants evolved an unparalleled plasticity in their post-embryonic development, allowing them to adapt and fine-tune their vital parameters to an ever-changing environment. Cross-talk between plants and their environment requires tight regulation of information exchange at the plasma membrane （PM）. Plasma membrane proteins mediate such communication, by sensing variations in nutrient availability, external cues as well as by controlled solute transport across the membrane border. Localiza-tion and steady-state levels are essential for PM protein function and ongoing research identified cis- and trans-acting determinants, involved in control of plant PM protein localization and turnover. In this overview, we summarize recent progress in our understanding of plant PM protein sorting and degradation via ubiquitylation, a post-translational and reversible modification of proteins. We highlight characterized components of the machinery involved in sorting of ubiquitylated PM proteins and discuss consequences of protein ubiquitylation on fate of selected PM proteins. Specifically, we focus on the role of ubiquitylation and PM protein degradation in the regulation of polar auxin transport （PAT）. We combine this regulatory circuit with further aspects of PM protein sorting control, to address the interplay of events that might control PAT and polarized growth in higher plants.展开更多
In both unicellular and multicellular organisms, transmembrane （TM） proteins are sorted to and retained at specific membrane domains by endomembrane trafficking mechanisms that recognize sorting signals in the these...In both unicellular and multicellular organisms, transmembrane （TM） proteins are sorted to and retained at specific membrane domains by endomembrane trafficking mechanisms that recognize sorting signals in the these proteins. The trafficking and distribution of plasma membrane （PM）-localized TM proteins （PM proteins）, especially of those PM proteins that show an asymmetric distribution over the PM, has received much attention, as their proper PM localization is crucial for elementary signaling and transport processes, and defects in their localization often lead to severe disease symptoms or developmental defects. The subcellular localization of PM proteins is dynamically regulated by post-translational modifications, such as phosphorylation and ubiquitination. These modificaitons mostly occur on sorting signals that are located in the larger cytosolic domains of the cargo proteins. Here we review the effects of phosphorylation of PM proteins on their trafficking, and present the key examples from the animal field that have been subject to studies for already several decades, such as that of aquaporin 2 and the epidermal growth factor receptor. Our knowledge on cargo trafficking in plants is largely based on studies of the family of PIN FORMED （PIN） carriers that mediate the efflux of the plant hormone auxin. We will review what is known on the subcellular distribution and trafficking of PIN proteins, with a focus on how this is modulated by phosphorylation, and identify and discuss analogies and differences in trafficking with the well-studied animal examples.展开更多
Polar auxin transport, which is required for the formation of auxin gradients and directional auxin flows that are critical for plant pattern formation, morphogenesis, and directional growth response to vectorial cues...Polar auxin transport, which is required for the formation of auxin gradients and directional auxin flows that are critical for plant pattern formation, morphogenesis, and directional growth response to vectorial cues, is mediated by polarized sub-cellular distribution of PIN-FORMED Proteins （PINs, auxin efflux carriers）, AUX1/AUXI-like proteins （auxin influx facilitators）, and multidrug resistance P-glycoproteins （MDR/PGP）. Polar localization of these proteins is controlled by both developmental and environmental cues. Recent studies have revealed cellular （endocytosis, transcytosis, and endosomal sorting and recycling） and molecular （PINOID kinase, protein phosphatase 2A） mechanisms underlying the polar distribution of these auxin transport proteins. Both TIR1-mediated auxin signaling and TIRl-independent auxinmediated endocytosis have been shown to regulate polar PIN localization and auxin flow, implicating auxin as a selforganizing signal in directing polar transport and directional flows.展开更多
文摘Objective： To investigate the expressions and correlations of Pin1, β-catenin and cyclin D1 in elderly lung carcinomas. Methods： The expressions of Pin1, β-catenin and cyclin D1 were examined in the specimens of 92 elderly lung carcinomas and 10 normal lung tissues by immunohistochemistry and explored the relationship between the expression levels and clinicopathological factors. Results： （1） The overexpression of Pin1 and cyclin D1 in lung carcinomas was 46 （50%） cases and 60 （65.22%） cases respectively and 56 （60.82%） cases showed positive immunoreactivity for 13-catenin in the nuclear and （or） cytoplasmic fraction in tumor tissues. In normal tissue, the expressions of Pin1 and cyclin D1 were negative, the expression of β-catenin was lied in cell membrane. （2） In lung carcinomas the expressions of Pin1, β-catenin and cyclin D1 correlated with tumor differentiation （P 〈 0.05）. The pesitive expression rate and intensity of Pin1 correlated with tumor stage （P = 0.032） and lymph node positive disease （P = 0.041）. The expression of β-catenin correlated with lymph node positive disease （P = 0.012）. （3） High expression levels of Pin1 correlated with aberrant I]-catenin expression （P = 0.000） but did not show a correlation with cyclin D1 （P = 0.157）. Conclusion： In elderly lung carcinomas, the positive expression of Pin1 causes abnormal accumulation of β-catenin and actives its target gene, however, this target gene was not cyclin DI. The detection of Pin1 expression had some clinical significance in estimating prognosis of elderly patient with lung carcinomas.
基金B.K. is supported by the Hertha Firnberg program from the Austrian Science Fund (FWF, T477)Work in the lab of C.L. is supported by FWF grants P19585 and P25931
文摘Being sessile organisms, plants evolved an unparalleled plasticity in their post-embryonic development, allowing them to adapt and fine-tune their vital parameters to an ever-changing environment. Cross-talk between plants and their environment requires tight regulation of information exchange at the plasma membrane （PM）. Plasma membrane proteins mediate such communication, by sensing variations in nutrient availability, external cues as well as by controlled solute transport across the membrane border. Localiza-tion and steady-state levels are essential for PM protein function and ongoing research identified cis- and trans-acting determinants, involved in control of plant PM protein localization and turnover. In this overview, we summarize recent progress in our understanding of plant PM protein sorting and degradation via ubiquitylation, a post-translational and reversible modification of proteins. We highlight characterized components of the machinery involved in sorting of ubiquitylated PM proteins and discuss consequences of protein ubiquitylation on fate of selected PM proteins. Specifically, we focus on the role of ubiquitylation and PM protein degradation in the regulation of polar auxin transport （PAT）. We combine this regulatory circuit with further aspects of PM protein sorting control, to address the interplay of events that might control PAT and polarized growth in higher plants.
基金F.H. was supported by grants from the China Scholarship Councilthe Research Council for Chemical Sciences (700.58.301 to R.O.) with fnancial aid from The Netherlands Organization for Scientifc Research
文摘In both unicellular and multicellular organisms, transmembrane （TM） proteins are sorted to and retained at specific membrane domains by endomembrane trafficking mechanisms that recognize sorting signals in the these proteins. The trafficking and distribution of plasma membrane （PM）-localized TM proteins （PM proteins）, especially of those PM proteins that show an asymmetric distribution over the PM, has received much attention, as their proper PM localization is crucial for elementary signaling and transport processes, and defects in their localization often lead to severe disease symptoms or developmental defects. The subcellular localization of PM proteins is dynamically regulated by post-translational modifications, such as phosphorylation and ubiquitination. These modificaitons mostly occur on sorting signals that are located in the larger cytosolic domains of the cargo proteins. Here we review the effects of phosphorylation of PM proteins on their trafficking, and present the key examples from the animal field that have been subject to studies for already several decades, such as that of aquaporin 2 and the epidermal growth factor receptor. Our knowledge on cargo trafficking in plants is largely based on studies of the family of PIN FORMED （PIN） carriers that mediate the efflux of the plant hormone auxin. We will review what is known on the subcellular distribution and trafficking of PIN proteins, with a focus on how this is modulated by phosphorylation, and identify and discuss analogies and differences in trafficking with the well-studied animal examples.
文摘Polar auxin transport, which is required for the formation of auxin gradients and directional auxin flows that are critical for plant pattern formation, morphogenesis, and directional growth response to vectorial cues, is mediated by polarized sub-cellular distribution of PIN-FORMED Proteins （PINs, auxin efflux carriers）, AUX1/AUXI-like proteins （auxin influx facilitators）, and multidrug resistance P-glycoproteins （MDR/PGP）. Polar localization of these proteins is controlled by both developmental and environmental cues. Recent studies have revealed cellular （endocytosis, transcytosis, and endosomal sorting and recycling） and molecular （PINOID kinase, protein phosphatase 2A） mechanisms underlying the polar distribution of these auxin transport proteins. Both TIR1-mediated auxin signaling and TIRl-independent auxinmediated endocytosis have been shown to regulate polar PIN localization and auxin flow, implicating auxin as a selforganizing signal in directing polar transport and directional flows.
