Microinjection of the nonhistone chromosomal protein hmg1 into bovine fibroblasts and hela cells

Rechsteiner, Martin; Kuehl, LeRoy

doi:10.1016/0092-8674(79)90105-3

Cited by 100 publications

(57 citation statements)

References 43 publications

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“…For example, in human lymphocyte-mouse ES cell heterokaryons, the ES cell transcription factor OCT4 is loaded onto lymphocyte chromatin 37 , and this is required for transcriptional reprogramming of the lymphocyte. Similarly, structural components of chromatin, such as HMG proteins, are efficiently exchanged between the nuclei of a heterokaryon 38 . Of note, the highly mobile histone H1 is not exchanged between the nuclei of a heterokaryon 39 ; this is in sharp contrast to the highly efficient loading of this component onto nuclei transplanted to eggs and oocytes 11,26,27 .…”

Section: Changes In Chromosomal Proteinsmentioning

confidence: 99%

Mechanisms of nuclear reprogramming by eggs and oocytes: a deterministic process?

Jullien

Pasque²,

Halley-Stott³

et al. 2011

Nat Rev Mol Cell Biol

106

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Differentiated cells can be experimentally reprogrammed back to pluripotency by nuclear transfer, cell fusion or induced pluripotent stem cell technology. Nuclear transfer and cell fusion can lead to efficient reprogramming of gene expression. The egg and oocyte reprogramming process includes the exchange of somatic proteins for oocyte proteins, the post-translational modification of histones and the demethylation of DNA. These events occur in an ordered manner and on a defined timescale, indicating that reprogramming by nuclear transfer and by cell fusion rely on deterministic processes.The remarkable stability of cell differentiation under normal conditions can be reversed experimentally by nuclear transfer, cell fusion and induced pluripotent stem (iPS) cell technology [1][2][3][4][5] . This provides an opportunity to generate pluripotent embryonic cells from adult cells of the same individual and hence opens the possibilit y of cell replacement without the need for immunosuppression.iPS cell technology makes use of the overexpression of transcription factors (FIG. 1a) and has been extensively reviewed, so it is not discussed in detail [6][7][8][9] . To generate entirely unrelated cell types by iPS cell technology, treated cells must be grown for multiple cell divisions over a long period of time (up to 3 weeks). By contrast, nuclear transfer and cell fusion do not involve the overexpression of new genes, and instead make use of natura components present in eggs and some early embryos to initiate new transcription.There are two kinds of nuclear transfer experiments: egg-NT involves the transfer of a single somatic nucleus to an unfertilize d enucleated egg (in both mammals and amphibians) 1 (FIG. 1b); and ooc-NT involves the transplantation of multiple somatic cell nuclei into the germinal vesicle (the nucleus) of a growing meiotic prophase amphibian oocyte (an immature egg) 10 (FIG. 1c). Note that the terms egg and oocyte refer to different developmental stages in amphibians and mammals: amphibian eggs are in metaphase II of meiosis, which is equivalent to mouse metaphase II stage oocytes, whereas their immediate precursors, oocytes, are blocked in meiotic prophase I, which is equivalent to mouse germinal vesicle stage oocytes.© 2011 Macmillan Publishers Limited. All rights reserved Correspondence to J.B.G.j.gurdon@gurdon.cam.ac.uk. Competing interests statementThe authors declare no competing financial interests. There are important differences between the two types of nuclear transfer experimen t. Extensive cell division takes place in egg-NT experiments, and functional new cell types appear as the nuclear transplant embryo develops. By contrast, in ooc-NT experiments, no new cell types are formed, and neither the oocyte nor the introduced nuclei divide, but there is a direct transition from nuclei of differentiated cells to reprogrammed nuclei that transcribe pluripotency genes. Analysis of the mechanism of reprogramming (which involves transcription of pluripotency and other genes) in egg-NT expe...

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Section: Changes In Chromosomal Proteinsmentioning

confidence: 99%

Mechanisms of nuclear reprogramming by eggs and oocytes: a deterministic process?

Jullien

Pasque²,

Halley-Stott³

et al. 2011

Nat Rev Mol Cell Biol

106

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“…The HMGl and HMG2 proteins, however, are sufficiently small to pass the nuclear pores by diffusion (Dingwall and Laskey, 1986). Several studies have shown that microinjected HMGl and HMG2 were rapidly translocated from the cytoplasm to the nucleus within several minutes (Reichsteiner and Kuehl, 1979;Kuehl et al, 1985;Tsuneoka et al, 1986). Fusion of cells containing Y -H M G l and 1251-HMG2 proteins with unlabelled cells resulted in the translocation of a portion of the label into the unlabelled nuclei (Reichsteiner and Kuehl, 1979).…”

mentioning

confidence: 99%

DNA binding and nuclear translocation of insect high‐mobility‐group protein‐1 (HMG1) proteins are inhibited by phosphorylation

Wiśniewski

Schulze

Sapetto

1994

European Journal of Biochemistry

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The cells of the dipteran insects Chironomus and Drosophila contain high-mobility-group proteins (HMG) that are homologous to the HMGl proteins of mammals, but contain only one HMGl box instead of two. The C-terminal portions of both mammalian and insect HMGl proteins comprise many charged residues that modulate the DNA-binding affinity of the HMGl boxes and were found in Chironomus to be substrates for protein kinase C (PKC) in vitro and in vivo. Phosphorylation of Chironomus HMGl proteins cHMGla and cHMGlb by PKC resulted in a tenfold and fivefold reduction, respectively, of the DNA-binding strength. Phosphorylated and unphosphorylated cHMGl a protein was labelled with fluoresceine isothiocyanate and microinjected into the cytoplasm of Chironomus salivary gland cells. The translocation of phosphorylated cHMGla into the nuclei was found to be remarkably delayed as compared to that of the unmodified form. The distribution of HMGl proteins between nucleus and cytoplasm is known to vary according to the cell type and the state of differentiation. Our results suggest that this distribution may be regulated by changing the efficiency of nuclear translocation and the affinity for DNA via phosphorylation and dephosphorylation.

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“…The discovery of techniques for fusing tissue culture cells from two different sources made similar studies possible on nuclei of higher organisms, with considerably more control over experimental conditions. The transfer of proteins from one nucleus to the other in such heterokaryons can be demonstrated by radioactive label (Rechsteiner and Kuehl, 1979), by speciesspecific antibodies (Borer et al, 1989;Piñ ol-Roma and Dreyfuss, 1991), or by epitope tags on transiently expressed proteins (Cáceres et al, 1998). Depending on the species, the nuclei can be distinguished by morphological or biochemical markers.…”

Section: Detection Of Shuttling Proteinsmentioning

confidence: 99%

Coilin Shuttles between the Nucleus and Cytoplasm InXenopusOocytes

Bellini

Gall

1999

MBoC

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Coiled bodies are discrete nuclear organelles often identified by the marker protein p80-coilin. Because coilin is not detected in the cytoplasm by immunofluorescence and Western blotting, it has been considered an exclusively nuclear protein. In the Xenopus germinal vesicle (GV), most coilin actually resides in the nucleoplasm, although it is highly concentrated in 50 -100 coiled bodies. When affinity-purified anti-coilin antibodies were injected into the cytoplasm of oocytes, they could be detected in coiled bodies within 2-3 h. Coiled bodies were intensely labeled after 18 h, whereas other nuclear organelles remained negative. Because the nuclear envelope does not allow passive diffusion of immunoglobulins, this observation suggests that anti-coilin antibodies are imported into the nucleus as an antigen-antibody complex with coilin. Newly synthesized coilin is not required, because cycloheximide had no effect on nuclear import and subsequent targeting of the antibodies. Additional experiments with myc-tagged coilin and myc-tagged pyruvate kinase confirmed that coilin is a shuttling protein. The shuttling of Nopp140, NO38/B23, and nucleolin was easily demonstrated by the targeting of their respective antibodies to the nucleoli, whereas anti-SC35 did not enter the germinal vesicle. We suggest that coilin, perhaps in association with Nopp140, may function as part of a transport system between the cytoplasm and the coiled bodies. INTRODUCTIONIn 1903 the Spanish neurobiologist Ramó n y Cajal described small silver-staining organelles in the nuclei of pyramidal cells of the brain, which he called nucleolar accessory bodies, because they frequently associated with the prominent nucleolus (Cajal, 1903). The same structures were rediscovered more than 60 years later in nuclei of liver and other mammalian tissues by Monneron and Bernhard (1969), who named them coiled bodies, based on their appearance in electron micrographs. Very little was learned about the composition of these organelles until Raška et al. (1991) discovered autoimmune sera that stained them specifically. Using these sera, Andrade et al. (1991) cloned a gene encoding a protein, p80-coilin, that occurs in high concentration in coiled bodies. Once coilin became available as a molecular marker, coiled bodies were found to contain many RNA transcription and processing components, including all five of the splicing small nuclear ribonucleoprotein particles (snRNPs), U3 snRNA, U7 snRNA, and several nucleolar proteins, such as fibrillarin and Nopp140 (reviewed by Gall et al., 1995;Lamond and Earnshaw, 1998;Matera, 1998). Possible functions of coiled bodies have been discussed extensively. We have presented evidence that coiled bodies recruit the U7 snRNP and the stem-loop-binding protein (SLBP1) to the chromosomal sites of histone gene transcription (Wu et al., 1996;Bellini and Gall, 1998;Abbott et al., 1999). In addition, they almost certainly play some role in splicing and pre-rRNA processing, such as assembly, modification, or storage of processing compon...

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Microinjection of the nonhistone chromosomal protein hmg1 into bovine fibroblasts and hela cells

Cited by 100 publications

References 43 publications

Mechanisms of nuclear reprogramming by eggs and oocytes: a deterministic process?

Mechanisms of nuclear reprogramming by eggs and oocytes: a deterministic process?

DNA binding and nuclear translocation of insect high‐mobility‐group protein‐1 (HMG1) proteins are inhibited by phosphorylation

Coilin Shuttles between the Nucleus and Cytoplasm InXenopusOocytes

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