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G H Goodwin

Publications and source records attributed to G H Goodwin.

At least 55 records · Page 3Linked to original sources
PubMed1983

Comparison of the high-mobility-group chromosomal proteins in rainbow-trout (Salmo gairdnerii) liver and testis.

Chromatography and characterization of the proteins extracted by 5% (w/v) HClO4 from rainbow-trout (Salmo gairdnerii) liver and testis show that the two tissues present a characteristically different spectrum of high-mobility-group (HMG) proteins. A variant subfraction of HMG C is found in liver, but is not detectable in testis, where even the main fraction of HMG C is present in only very low quantity. A protein, F, which appears to be related to protein H6 has similarly been isolated only from liver and not from testis. Quantification of the HMG proteins in total 5%-HClO4 extracts of trout liver and testis nuclei shows that, in relation to DNA, levels of HMG T1 and T2, and D are more than 2-fold, and C, 20-fold higher in liver than in testis. However, these differences do not result merely from the sequential withdrawal of HMG proteins at the same time that histones are replaced by protamines in the developing spermatid, since in testis, at some stages of maturation, levels of H6 are almost 2-fold higher than in liver. The implications of these findings for the function of HMG proteins are discussed.

Amino Acids↗
PubMed1983

Isolation from trout liver of a methionine-containing H1 subfraction, THImet.

A trout H1 subfraction, THImet, which contains one residue of methionine and a blocked N-terminal amino acid, has been isolated from trout liver. Cyanogen bromide cleavage of THImet and amino acid analysis and polyacrylamide gel electrophoresis of the cleavage products show that it contains a residue of methionine at about the same distance from the N terminus as mammalian H1o and avian H5. THImet is shown to be similar to, but not identical with, the protein derived from trout erythrocytes generally accepted as the equivalent in fish of avian H5.

Animals↗
PubMed1983

Comparisons of the structures of the chromosomal high mobility group proteins HMG1 and HMG2 prepared under conditions of neutral and acidic pH.

The chromosomal proteins HMG1 and 2 have been prepared by salt extraction and phosphocellulose chromatography at neutral pH (Isackson, P.J., Debold, W.A. and Reeck, G.R. (1980) FEBS Lett. 119, 337-342) to minimize protein denaturation. The structures of these phosphocellulose-prepared high mobility group proteins have been compared with those of high mobility group proteins using the previously described acid-extraction conditions which fully denature the proteins. When compared in the same solvent conditions the acid-extracted proteins did not refold to give the same level of alpha-helical and tertiary folded structures as the phosphocellulose-prepared proteins, suggesting that acid treatment can cause some irreversible damage to the proteins. This finding was supported by changes in the structure observed when phosphocellulose-prepared HMG1 was neutralized after exposure to acid. Gel filtration studies reveal no differences in the size of the high mobility group proteins, phosphocellulose-prepared and acid-extracted proteins both being largely monomeric in solution. Little difference was detected in the DNA-binding properties of the two types of protein, nor was there any difference in the oxidation state of the cysteines. However, isoelectric focusing analysis revealed differences in the subfractions of HMG2 prepared by the two methods.

Animals↗
PubMed1983

Effect of HMG protein 17 on the thermal stability of control and acetylated HeLa oligonucleosomes.

Many studies have implicated histone acetylation and HMG proteins 14 and 17 in the structure of active chromatin. Studies of the binding of HMG 14 and 17 to chromatin core particles have shown that there are two binding sites for HMG 14 or 17 located within 20-25 bp of the DNA ends of the core particles [13-15]. Such binding sites may result from the free DNA ends in the core particle being available for the binding of HMG 14 and 17. We have studied the effects of the binding of HMG 17 on the thermal denaturation of DNA in mono, di and trinucleosomes. In each case the binding of 1 HMG 17 molecule per nucleosome reduces the DNA premelt region by 50%, while the binding of 2 HMG 17 molecules per nucleosome abolishes the premelt region. From this it is concluded that there are two HMG 17 binding sites per nucleosome which are located between the entry and exit points to the nucleosome and the strongly complexed central DNA region. Highly acetylated mono, di and trinucleosomes have been isolated from butyrate treated HeLa S3 cells. For this series of acetylated oligonucleosomes, it has been found that there are also two HMG 17 binding sites per acetylated nucleosome.

Acetylation↗
PubMed1983

Demonstration of an S1-nuclease sensitive site near the human beta-globin gene, and its protection by HMG 1 and 2.

An S1-nuclease sensitive site exists within supercoiled plasmids containing the 5'-flanking sequences of the human beta-globin gene. This site is located approximately 540 base pairs upstream from the start of the gene within a region of 52 alternating purine-pyrimidine residues which has the potential to adopt either cruciform structures or Z-form DNA. This site is protected from specific cleavage by S1-nuclease by the high-mobility-group chromosomal proteins HMG1 and 2, which may be specifically acting to protect short sequences of single-stranded DNA.

Base Sequence↗
PubMed1983

The nuclease sensitivity of active genes.

Brief micrococcal nuclease digestion of chick embryonic red blood cells results in preferential excision and solubilization of monomer nucleosomes associated with beta-globin sequences and also 5'-sequences flanking the beta-globin gene. Both regions are DNAse-I sensitive in nuclei. Such salt-soluble nucleosomes are enriched in all four major HMG proteins but HMG1 and 2 are only weakly associated. These nucleosomes appear to have lost much of the DNAse-I sensitivity of active genes. The HMG14 and 17-containing salt-soluble nucleosomes separated by electrophoresis are not DNAse-I sensitive and contain inactive gene sequences as well as active sequences. Reconstitution of HMG proteins onto bulk nucleosomes or chromatin failed to reveal an HMG-dependent sensitivity of active genes as assayed by dot-blot hybridization and it was found that the DNAse-I sensitivity of ASV proviral sequences as assayed by dot-blot hybridization was not HMG-dependent. These results indicate that higher order chromatin structures might be responsible for nuclease sensitivity of active genes.

Animals↗
PubMed1981

The characterisation of 1SF monomer nucleosomes from hen oviduct and the partial characterisation of a third HMG14/17-like in such nucleosomes.

Nucleosomes released from oviduct nuclei during brief micrococcal nuclease digestions are enriched in transcribed sequences (bloom K.S. and Anderson, J.N. (1978) Cell, 15, 141-150). Such nucleosomes released into this 1Sf supernatant fraction are enriched in proteins HMG14, 17 and a third lower molecular weight protein which we show in this paper to be related to HMG14 and 17. This protein, which we call HMGY, runs as a doublet on polyacrylamide gels. A similar doublet is present in smaller quantities in chicken erythrocyte nuclei. Monomer nucleosomes in the 1SF supernatant have been separated by polyacrylamide gel electrophoresis into two main bands. The slower moving band contains the three HMG proteins HMG14, 17 and Y but lacks histone H1.

Amino Acids↗
PubMed1981

The high mobility group proteins and transcribed nucleosomes.

Monomer nucleosomes released from nuclei during brief micrococcal nuclease digestions are enriched in transcribed sequences (Bloom and Anderson, 1978). These nucleosomes are depleted in H1 and enriched in three high mobility group proteins HMG14, HMG17 and another HMG-like protein. Analysis of such nucleosomes by polyacrylamide gel electrophoresis reveal that they are heterogenous. Similarly, monomer nucleosomes soluble in 0.1 M NaCl separate on polyacrylamide gels into mainly two types of particle, one of which has HMG14 and HMG17 bound. However, the DNA of the HMG-nucleosomes from chick erythrocytes is not enriched in globin sequences, suggesting that protein rearrangement may have occurred.

Animals↗
PubMed1980

The isolation of three new high mobility group nuclear proteins.

In addition to the four high mobility group non-histone chromosomal proteins HMG 1, 2, 14 and 17 and histone H1, perchloric acid extracts of nuclei contain a number of other smaller low molecular weight proteins. Three of these proteins (HMG 18, 19A, and 19B) have been purified and characterized. Protein HMG 18 has high lysine and alanine contents, resembling histone H1. Proteins HMG 19A and 19B have high contents of basic and acidic amino acids and resemble HMG proteins 1, 2, 14 and 17. N-terminal sequence analyses of the proteins show that they are not degradation products of histones or the other HMG proteins. However, there are sequence similarities between HMG 18 and histone H5, and between HMG 19B and HMG 17, supporting the view that the HMG proteins and the lysine-rich histones are functionally related.

Amino Acid Sequence↗
PubMed1980

Structural studies on two high-mobility-group proteins from calf thymus, HMG-14 and HMG-20 (ubiquitin), and their interaction with DNA.

High mobility group (HMG) protein 14, which, like HMG-17, has been implicated in the structure of 'active chromatin' is shown by 270-MHz NMR and by circular dichroism to be in a disordered conformation in free solution. At low ionic strength protein HMG-14 binds to DNA by weak attachment of the N-terminal half of the molecule and is released by 0.3 M NaCl, the ionic strength at which the protein is extracted from chromatin. The protein HMG-20 (ubiquitin), a constituent of the conjugate protein A 24, is shown to be a highly stable compact globular protein that remains folded over a pH range of 1--13 and has a half-denaturation temperature of 85 degrees C when thermally denatured. Circular dichroism indicates 28% helix and 12% beta sheet. Despite having 15% basic residues it binds only very weakly to DNA. A detailed study of the folding of ubiquitin has been made by a combination of several NMR approaches, including decoupling, nuclear Overhauser enhancement and titration. Several line assignments have been made and it is shown that, although the tyrosine and histidine are buried residues, they are not adjacent to one another nor are they close to either of the phenylalanines, of which at least one is also a buried residue.

Amino Acid Sequence↗
PubMed1979

Analysis of the high mobility group proteins associated with salt-soluble nucleosomes.

Two methods have recently been described for the isolation of monomer nucleosomes enriched in transcribed sequences which depend on their solubility in 0.1 M NaCl (Levy, W.B. and Dixon (1978), Nucleic Acid Res., 5, 4155-4163) or solutions containing divalent metal ions (Bloom, K.S. and Anderson, J.N. (1978), Cell, 15, 141-150). Using these procedures the proteins associated with such nucleosomes from rabbit thymus, calf liver and hen oviduct nuclei were isolated and analysed. Increased amounts of proteins HMG14 AND HMG17 and small amounts of HMG1 and HMG2 were found associated with the four core histones H2A, H2B, H3 and H4 in these nucleosomes. HMG14 and HMG17 were found to be enriched 2 - 7 fold, suggesting an involvement of these two proteins with transcribed sequences. 0.1 M NaCl-soluble monomer nucleosomes prepared by the method of Levy and Dixon were analysed by polyacrylamide gel electrophoresis and found to be composed of principally two types of particle: 1. Core particles of 145 base pairs of DNA associated with the four core histones only. 2. Nucleosomes with 160 base pairs of DNA associated with the four core histones, increased amounts of HMG14 and 17, and no H1. Small amounts of HMG1 and HMG2 are also detected. These results suggest that HMG14 and HMG17 might be interacting with the 15 base pair linker DNA. A model is presented for the structure of transcriptionally active chromatin.

Animals↗
PubMed1979

Does high-mobility-group non-histone protein HMG 1 interact specifically with histone H1 subfractions?

The interaction of the non-histone chromosomal protein HMG (high-mobility group) 1 with histone H1 subfractions was investigated by equilibrium sedimentation and n.m.r. sectroscopy. In contrast with a previous report [Smerdon & Isenberg (1976) Biochemistry 15, 4242--4247], it was found, by using equilibrium-sedimentation analysis, that protein HMG 1 binds to all three histone H1 subfractions CTL1, CTL2, and CTL3, arguing against there being a specific interaction between protein HMG 1 and only two of the subfractions, CTL1 and CTL2. Raising the ionic strength of the solutions prevents binding of protein HMG 1 to total histone H1 and the three subfractions, suggesting that the binding in vitro is simply a non-specific ionic interaction between acidic regions of the non-histone protein and the basic regions of the histone. Protein HMG 1 binds to histone H5 also, supporting this view. The above conclusions are supported by n.m.r. studies of protein HMG 1/histone H1 subfraction mixtures. When the two proteins were mixed, there was little perturbation of the n.m.r. spectra and there was no evidence for specific interaction of protein HMG 1 with any of the subfractions. It therefore remains an open question as to whether protein HMG 1 and histone H1 are complexed together in chromatin.

Centrifugation, Density Gradient↗