Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Molecular Biology

SelectedWorks

Selected Works

Keyword
Publication Year
Publication
File Type

Articles 61 - 65 of 65

Full-Text Articles in Life Sciences

The Processing Pathway Of Prelamin A, Michael Sinensky, K. Fantle, M. Trujillo, T. Mclain, A. Kupfer, M. Dalton Jan 1994

The Processing Pathway Of Prelamin A, Michael Sinensky, K. Fantle, M. Trujillo, T. Mclain, A. Kupfer, M. Dalton

Michael Sinensky

The conversion of mammalian prelamin A to mature lamin A proceeds through the removal of 18 amino acids from the carboxyl terminus. The initial step in this processing is the isoprenylation of a CAAX box cysteine. This proteolytic event is distinctive for prelamin A among the known prenylated mammalian proteins. Since the carboxyl terminus of prelamin A is removed during maturation, it is not obvious that this protein would undergo the two reactions subsequent to prenylation observed in other CAAX box proteins-the endoproteolytic removal of the carboxyl-terminal 3 amino acids and the subsequent methylation of the now carboxyl-terminal cysteine. To …


Functional Explanation And Metaphysical Individualism, Justin Schwartz Jan 1993

Functional Explanation And Metaphysical Individualism, Justin Schwartz

Justin Schwartz

A number of (present or former) analytical Marxists, such as Jon Elster, have argued that functional explanation has almost no place in the social sciences. (Although the discussion is framed in terms of a debate among analytical Marxists, the point is quite general, and Marxism is used for illustrative purposes.) Functional explanation accounts for what is to be explained by reference to its function; thus, sighted organism have eyes because eyes enable them to see. Elster and other critics of functional explanation argue that this pattern of explanation is inconsistent with "methodological individualism," the idea, as they understand it, that …


Isoprenylation Is Required For The Processing Of The Lamin A Precursor, Michael Sinensky, L. A. Beck, T. J. Hosick Jan 1990

Isoprenylation Is Required For The Processing Of The Lamin A Precursor, Michael Sinensky, L. A. Beck, T. J. Hosick

Michael Sinensky

The nuclear lamina proteins, prelamin A, lamin B, and a 70-kD lamina-associated protein, are posttranslationally modified by a metabolite derived from mevalonate. This modification can be inhibited by treatment with (3-R,S)-3-fluoromevalonate, demonstrating that it is isoprenoid in nature. We have examined the association between isoprenoid metabolism and processing of the lamin A precursor in human and hamster cells. Inhibition of 3-hydroxy-3-methylglutaryl coenzyme A reductase by mevinolin (lovastatin) specifically depletes endogenous isoprenoid pools and inhibits the conversion of prelamin A to lamin A. Prelamin A processing is also blocked by mevalonate starvation of Mev-1, a CHO cell line auxotrophic for mevalonate. …


Incorporation Of A Product Of Mevalonic Acid Metabolism Into Proteins Of Chinese Hamster Ovary Nuclei, Michael Sinensky, L. A. Beck, T. Hosick Jan 1988

Incorporation Of A Product Of Mevalonic Acid Metabolism Into Proteins Of Chinese Hamster Ovary Nuclei, Michael Sinensky, L. A. Beck, T. Hosick

Michael Sinensky

We have examined the nuclear localization of isoprenylated proteins in CHO-K1 cells labeled with [14C]mevalonate. Nuclear proteins of 68, 70, and 74 kD, posttranslationally modified by an isoprenoid, are also components of a nuclear matrix-intermediate filament preparation from CHO cells. Furthermore, the 68-, 70-, and 74-kD isoprenylated polypeptides are immunoprecipitated from cell extracts with two different anti-lamin antisera. Based on exact two-dimensional comigration with lamin B, both from rat liver lamin and CHO nuclear matrix-intermediate filament preparations, and its immunoprecipitation with anti-lamin antisera, we conclude that the 68-kD isoprenylated protein found in nuclei from [14C]mevalonate-labeled CHO cells is lamin B. …


Adaptative Alteration In Phospholipid Composition Of Plasma Membranes From A Somatic Cell Mutant Defective In The Regulation Of Cholesterol Biosynthesis, Michael Sinensky Jan 1980

Adaptative Alteration In Phospholipid Composition Of Plasma Membranes From A Somatic Cell Mutant Defective In The Regulation Of Cholesterol Biosynthesis, Michael Sinensky

Michael Sinensky

A somatic cell mutant (CR1) of a Chinese hamster ovary cell (CHO-K1) which has previously been shown to be defective in the regulation of cholesterol biosynthesis accumulates more cholesterol than the parental cell line in plasma membranes. Although such an increase in membrane cholesterol should lead to an increase in the order parameter of these membranes, as measured with an electron spin resonance spin probe, the order parameters of mutant and wild-type plasma membranes are identical--apparently because of an adaptive alteration in membrane phospholipid composition. The phospholipid compositions of mutant and wild-type cell plasma membranes are compared and the mutant …