IF-like proteins have been obtained from suspension cells of Nicotiana tabacum by selective extraction. Western blot analysis shows that the major components of IF-like proteins are 6 keratin-like proteins of 64, 58, ...IF-like proteins have been obtained from suspension cells of Nicotiana tabacum by selective extraction. Western blot analysis shows that the major components of IF-like proteins are 6 keratin-like proteins of 64, 58, 55, 54, 50 and 45 ku. Specially the 50 ku ptotein also reacts with polyantibody against microtublin. Two-dimensional gel electrophoresis shows that the 50 ku protein is composed of two different proteins and their amino acid sequences have been determined. Part of the sequence of one protein is identical to that of β-microtublin and the other protein’s sequence has no significant homologue, which should be a new sequence-unknown protein. These results suggest that 50 ku keratin-like protein and β-microtublin coexist in higher plant cells, and that may lead to the phenomenon of co-distribution of IF and microtuble in plant cells.展开更多
Ⅰ. INTRODUCTION Intermediate filaments with a diameter of 10 nm, known as a cytoskeleton system, are extensively present in animal cells. Whether the intermediate filaments are present in plant cells remains to be a ...Ⅰ. INTRODUCTION Intermediate filaments with a diameter of 10 nm, known as a cytoskeleton system, are extensively present in animal cells. Whether the intermediate filaments are present in plant cells remains to be a question. Some investigators attempt to seek answers from various aspects, but it is still unsolved. Powell observed 7-nm filament in carrot suspension cells after treatment with high salt and Triton X-100. Dawson and Miller showed展开更多
Two keratin-like proteins of 64 and 55 ku were purified from suspension cells of Caucus carota L, and their partial amino acid sequences were determined. The homological analysis showed that the sequence from the 64 k...Two keratin-like proteins of 64 and 55 ku were purified from suspension cells of Caucus carota L, and their partial amino acid sequences were determined. The homological analysis showed that the sequence from the 64 ku protein was highly homological to p-glucosidase, and that from the 55 ku protein had no significant homologue in GenBank. Using conservative sequence of animal IF proteins as primer, we cloned a cDNA fragment from Daucus carota L. Southern blot and Northern blot results indicated that this cDNA fragment was a single copy gene and expressed both in suspension cells and leaves. Homological analysis revealed that it had moderate homology to a variety of a-helical proteins. Our results might shed more light on molecular characterization of IF existence in higher plant.展开更多
The application of Penman's method of cell fractionation to plant protoplasts leads to our finding of keratin intermediate filament(IF)-like system in maize protoplasts,which was identified by using immunogold lab...The application of Penman's method of cell fractionation to plant protoplasts leads to our finding of keratin intermediate filament(IF)-like system in maize protoplasts,which was identified by using immunogold labelling with monoclonal antibody of cytokeratin from animal cells.Many gold particles were found to be bound on filaments,linked by 3 nm filaments.After further digestion and extraction with DNase I and ammonium sulphate.IF-like framework-lamina-nuclear matrix system was shown under electron microscope.That IF system exists in plant protoplasts just like in animal cells,and their main component is keratin-like protein.展开更多
文摘IF-like proteins have been obtained from suspension cells of Nicotiana tabacum by selective extraction. Western blot analysis shows that the major components of IF-like proteins are 6 keratin-like proteins of 64, 58, 55, 54, 50 and 45 ku. Specially the 50 ku ptotein also reacts with polyantibody against microtublin. Two-dimensional gel electrophoresis shows that the 50 ku protein is composed of two different proteins and their amino acid sequences have been determined. Part of the sequence of one protein is identical to that of β-microtublin and the other protein’s sequence has no significant homologue, which should be a new sequence-unknown protein. These results suggest that 50 ku keratin-like protein and β-microtublin coexist in higher plant cells, and that may lead to the phenomenon of co-distribution of IF and microtuble in plant cells.
基金Project supported by the National Natural Science Foundation of China
文摘Ⅰ. INTRODUCTION Intermediate filaments with a diameter of 10 nm, known as a cytoskeleton system, are extensively present in animal cells. Whether the intermediate filaments are present in plant cells remains to be a question. Some investigators attempt to seek answers from various aspects, but it is still unsolved. Powell observed 7-nm filament in carrot suspension cells after treatment with high salt and Triton X-100. Dawson and Miller showed
文摘Two keratin-like proteins of 64 and 55 ku were purified from suspension cells of Caucus carota L, and their partial amino acid sequences were determined. The homological analysis showed that the sequence from the 64 ku protein was highly homological to p-glucosidase, and that from the 55 ku protein had no significant homologue in GenBank. Using conservative sequence of animal IF proteins as primer, we cloned a cDNA fragment from Daucus carota L. Southern blot and Northern blot results indicated that this cDNA fragment was a single copy gene and expressed both in suspension cells and leaves. Homological analysis revealed that it had moderate homology to a variety of a-helical proteins. Our results might shed more light on molecular characterization of IF existence in higher plant.
文摘The application of Penman's method of cell fractionation to plant protoplasts leads to our finding of keratin intermediate filament(IF)-like system in maize protoplasts,which was identified by using immunogold labelling with monoclonal antibody of cytokeratin from animal cells.Many gold particles were found to be bound on filaments,linked by 3 nm filaments.After further digestion and extraction with DNase I and ammonium sulphate.IF-like framework-lamina-nuclear matrix system was shown under electron microscope.That IF system exists in plant protoplasts just like in animal cells,and their main component is keratin-like protein.
