Extremely rapid and reversible optogenetic perturbation of nuclear proteins in living embryos

Dark field electron microscopy has been used for the study of the structure of individual macromolecules with a resolution to at least the 5Å level. The use of this technique has been extended to the investigation of structure of interacting molecules, particularly the interaction between DNA and fish protamine, a class of basic nuclear proteins of molecular weight 4,000 daltons.Protamine, which is synthesized during spermatogenesis, binds to chromatin, displaces the somatic histones and wraps up the DNA to fit into the small volume of the sperm head. It has been proposed that protamine, existing as an extended polypeptide, winds around the minor groove of the DNA double helix, with protamine's positively-charged arginines lining up with the negatively-charged phosphates of DNA. However, viewing protamine as an extended protein is inconsistent with the results obtained in our laboratory.

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Nuclear proteins in primary biliary cirrhosis as guardians against HCC development

Zeitschrift für Gastroenterologie ◽

10.1055/s-0032-1332068 ◽

2013 ◽

Vol 51 (01) ◽

Author(s):

C Hintemann ◽

K Straub ◽

S Biesterfeld ◽

PR Galle ◽

J Erthle ◽

...

Keyword(s):

Primary Biliary Cirrhosis ◽

Nuclear Proteins ◽

Biliary Cirrhosis

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GENE ACTIVATION IN MAMMARY CELLS

Acta Endocrinologica ◽

10.1530/acta.0.071s346 ◽

1972 ◽

Vol 71 (2_Suppla) ◽

pp. S346-S368 ◽

Cited By ~ 4

Author(s):

Roger W. Turkington ◽

Nobuyuki Kadohama

Keyword(s):

Cell Differentiation ◽

Gene Transcription ◽

Hormonal Regulation ◽

Gene Activation ◽

Milk Proteins ◽

Mouse Mammary Gland ◽

Nuclear Proteins ◽

Mammary Cells ◽

Alveolar Cells ◽

Mammary Cell

ABSTRACT Hormonal activation of gene transcription has been studied in a model system, the mouse mammary gland in organ culture. Transcriptive activity is stimulated in mammary stem cells by insulin, and in mammary alveolar cells by prolactin and insulin. Studies on the template requirement for expression of the genes for milk proteins demonstrate that DNA methylation has an obligatory dependence upon DNA synthesis, but is otherwise independent from hormonal regulation of mammary cell differentiation. Incorporation of 5-bromo-2′deoxyuridine into DNA selectively inhibits expression of the genes for specific milk proteins. Undifferentiated mammary cells activate the synthesis of specific acidic nuclear proteins when stimulated by insulin. Several of these induced acidic nuclear proteins are undetectable in unstimulated undifferentiated cells, but appear to be characteristic components of the nuclei of differentiated cells. These results indicate that mammary cell differentiation is associated with a change in acidic nuclear proteins, and they provide evidence to support the concept that acidic nuclear proteins may be involved in the regulation of gene transcription and of mammary cell differentiation.

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