Search Results - (Author, Cooperation:J. Button)

2015-10-08

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

0014-4827

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource

0014-4827

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource

0014-4827

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Medicine

Electronic Resource

1573-4978

Springer Online Journal Archives 1860-2000

Biology

Abstract The acute phase reaction of rat liver to subcutaneous turpentine challenge results in a 20- to 100-fold increase in α1-acid glycoprotein (αAGP) mRNA. We utilized this response to establish conditions appropriate for study of RNA transport in vitro using hybridization with 32P-labeled exon and intron αAGP sequences. Contamination of nuclear preparations by membrane-absorbed cytoplasmic RNA was eliminated by detergent-rinsing. The in vitro incubation conditions that most reflected the in vivo state required RNase inhibitor (purified from placenta), polyvinylpyrrolidone to prevent nuclear swelling, and addition of ATP. Under these circumstances, αAGP sequences were transported only from turpentine-stimulated preparations, were found only in poly(A) + RNA, and were the same size as authentic cytoplasmic mRNA. Omission of polyvinylpyrrolidone resulted in release of some αAGP sequences in smaller, more heterogeneous poly(A)-RNA, and leakage of some αAGP sequences was observed from control preparations. Omission of ATP resulted in restriction of mature αAGP mRNA to the nucleus. In contrast to αAGP mRNA, transport of albumin mRNA was decreased 3-4X in turpentine-treated preparations. The largest αAGP intron was not found in RNA transported from treated nuclei in complete medium. The intron-containing fragments remained in the nucleus, largely in poly(A)- RNA of a size consistent with free intron. Some hybridization of intron sequences was observed with cytoplasmic and nuclear membrane-associated poly(A) + RNA preparations which may represent 3′-processing catabolites; leakage of these sequences was considerably greater in the absence of PVP. On the basis of densitometric estimates, a 5-fold increase in the amount of αAGP exon sequences was observed in nuclear RNA, comparing treated with control animals, but transport of αAGP exon sequences was detectable only from treated nuclei, indicating at least a 50-fold increase in abundance of αAGP sequences. This suggests that a selective gating mechanism may be operative at the level of post-transcriptional nucleocytoplasmic transport during induction of αAGP in the acute phase response.

Electronic Resource

1573-4978

Springer Online Journal Archives 1860-2000

Biology

Abstract A number of studies have documented substantial loss of nuclear protein during aqueous nuclear isolation procedures. This loss can, to some extent, be counteracted by addition of impermeable macromolecules like polyvinylpyrrolidone, which prevent nuclear swelling. While nucleic acids appear to be much less susceptible to leakage during isolation, the effects of these additives on RNA release duringin vitro incubation have not been examined. Here we show that addition of polyvinylpyrrolidone results in significant decreases in RNA transport; inhibition becomes maximal at 50–75 μM addition.

Electronic Resource

1432-2242

Springer Online Journal Archives 1860-2000

Biology

Summary A rapid method for differentiating between Citrus clones as well as between zygotic and nucellar plants has been developed. It is based on determination of peroxidase isoenzyme patterns in small root samples. Ten to 14 bands could be distinguished, in contrast to the small number of bands present in leaves. Tetraploid seedlings gave uniform patterns closely resembling the diploid, while triploids showed segregation in isozyme pattern.

Electronic Resource