Activator protein-1 complex

Moore, A.N., Kampfl, A.W., Zhao, X., Hayes, R.L. and Dash, P.K., 1999, Sphingosine 1-phosphate induces apoptosis of cultured hippocampal neuronsthat requires protein phosphatases and activator protein-1 complexes, 94 405-415. 

Yoneda Y., Ogita K., Azuma Y., Kuramoto N., Manabe T., and Kitayama T. (1999). Predominant expression of nuclear activator protein-1 complex with DNA binding activity following systemic administration ofN-methyl-D-aspartate in dentate granule cells of murine hippocampus. Neuroscience 93 19-31. 

This treatment also removes all three iron-sulfur proteins, FeS-X and FeS-A/B. Although this resulting complex has been referred to as CPI, here it will also be called the P700-chlorophyll a protein and may be considered as the simplest yet photochemically active protein complex of photosystem I. 

Soutourina, O., Kolb, A., Krin, E., Laurent-Winter, C., Rimsky, S., Danchin, A. and Bertin, R (1999). Multiple control of flagellum biosynthesis in Escherichia coli Role of H-NS protein and the cyclic AMP-cataboHte activator protein complex in transcription of theflhDC master operon. J. Bacteriol. 181, 7500-7508. Soutourina, O.A., Krin, E., Laurent-Winter, C., Hommais, R, Danchin, A. and Bertin, RN. (2002). Regulation of bacterial motility in response to low pH in Escherichia coli the role of H-NS protein. Microbiology 148, 1543-1551. 

In a pioneering paper on the cytochalasan molecular mode of action, Spudich and Lin discovered a decrease in viscosity of actomyosin from rabbit muscle - the active protein complex of actin and myosin - when treated with cytochalasin B (1088) in micromolar concentrations. Actin was identified as direct binding partner of cytochalasin B (1088), thus the first proof on the target of this compound was provided (705). Further studies by several groups revealed that cytochalasins B (1088) and D (1091) inhibit, but not completely arrest, actin filament elongation (708, 709). A plausible mechanism was proposed by Goddette and Frieden (710). 

Our laboratory has been involved in the identification and characterization of the transcription factors for RNA polymerase I (Pol I)-directed transcription of ribosomal RNA genes (rDNA). To this end, we initially isolated and partially purified a transcriptionally active protein complex which contains RNA polymerase I and the essential Pol I transcription factors (1). Such a fraction was obtained from whole ceU extracts (1) or from nuclear extracts (2). Subsequently, we demonstrated that a fraction obtained during chromatography of the cell extract on a heparin sepharose coliunn could prevent nonrandom transcription of cloned rat rDNA in an in vitro system (3). The major protein in this fraction exhibited characteristics of purified poly(ADP-ribose) polymerase. The present report summarizes the properties of this protein, and describes experiments showing the dramatic appearance of accurately initiated transcript in an unfiractionated whole ceU extract or nuclear extract from a tissue foUowing addition of the protein factor. 

A five fold molar excess of Kp2 over Kpl protein was used since this gave a maximum amplitude for the increase in extinction at 420 nm due to oxidation of Kp2 by a fixed concentration of Kpl. The amplitude of the burst phase for formation indicates that 2.3 mole equivalent of MgATP are hydrolysed per mole of Kpl reduced under these conditions. Uncertainties with regard to the percentage of the Kpl and Kp2 proteins which are active as electron acceptors and donors respectively, the stoichiometry of the active protein complex between Kpl and Kp2 and the number of electrons transferred by... 

Lead is toxic to the kidney, cardiovascular system, developiag red blood cells, and the nervous system. The toxicity of lead to the kidney is manifested by chronic nephropathy and appears to result from long-term, relatively high dose exposure to lead. It appears that the toxicity of lead to the kidney results from effects on the cells lining the proximal tubules. Lead inhibits the metaboHc activation of vitamin D in these cells, and induces the formation of dense lead—protein complexes, causing a progressive destmction of the proximal tubules (13). Lead has been impHcated in causing hypertension as a result of a direct action on vascular smooth muscle as well as the toxic effects on the kidneys (12,13). 

Weber, L, Steitz, T.A. The structure of a complex of catabo-lite gene activator protein and cyclic AMP refined at 2.S A resolution. /. Mol. Biol. 198 311-326, 1987. 

Rittinger, K. et al. Crystal structure of a small G protein in complex with GTPase-activating protein rhoGAP. Nature 388 693-697, 1997. 

Rittinger, K., et al. Structure at 1.65 A of RhoA and its GTPase-activating protein in complex with a transition-state analogue. Nature 389 758-762, 1997. 

Activator Protein-1 (API) comprises transcriptional complexes formed by dimers of members oftheFos, Jun, and ATF family of transcription factors. These proteins contain basic leucine zipper domains that mediate DNA binding and dimerization. They regulate many aspects of cell physiology in response to environmental changes. 

AMP-activated protein kinase, AMPK SNF1 complex (fungi) SNF1-related kinase-1 (higher plants)... 

AMP-activated protein kinases are heterotrimeric complexes comprised of catalytic a subunits and regulatory (3 and y subunits (Table 1). Each subunit is encoded by at least two genes, some of which can also be subject to alternate splicing, leading to a diverse array of possible heterotrimeric combinations. 

BH3 domain) of the BH3-only proteins binds to other Bcl-2 family members thereby influencing their conformation. This interaction facilitates the release of cytochrome C and other mitochondrial proteins from the intermembrane space of mitochondria. Despite much effort the exact biochemical mechanism which governs this release is not yet fully understood. The release of cytochrome C facilitates the formation of the apoptosome, the second platform for apoptosis initiation besides the DISC. At the apoptosome which is also a multi-protein complex the initiator caspase-9 is activated. At this point the two pathways converge. 

In addition to intracellular heme-containing proteins, big-conductance calcium-dependent K+ (BKCa) channels and calcium-spark activated transient Kca channels in plasma membrane are also tar geted by CO [3]. As well known, nitric oxide (NO) also activates BKca channels in vascular smooth muscle cells. While both NO and CO open BKCa channels, CO mainly acts on alpha subunit of BKCa channels and NO mainly acts on beta subunit of BKca channels in vascular smooth muscle cells. Rather than a redundant machinery, CO and NO provide a coordinated regulation of BKca channel function by acting on different subunits of the same protein complex. Furthermore, pretreatment of vascular smooth muscle... 

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