Autoreduction of Pure Spinach Cytochrome f: A Light-Dependent Process Inhibited by 3-(3,4-Dichlorophenyl)-1,1-dimethylurea

1974 ◽  
Vol 52 (1) ◽  
pp. 67-70 ◽  
Author(s):  
Harinder S. Garewal ◽  
Allan L. Stuart ◽  
Aaron R. Wasserman
Keyword(s):  
Membrane Protein ◽  
Cytochrome F ◽  
Dependent Process ◽  
Spinacea Oleracea ◽  
Complete Purification

A new procedure for the complete purification of spinach (Spinacea oleracea) cytochrome f, a tightly bound membrane protein, is described. The autoreduction of pure spinach cytochrome f has been confirmed using this new preparation. The process is now shown to be light-dependent and completely inhibited by the photosynthetic inhibitor 3-(3,4-dichlorophenyl)-1,1-dimethylurea. This inhibition is reversed by removing the inhibitor. The possible physiological implications of these observations are discussed.

Effect of prolonged anaerobiosis on 125I-insulin binding to rat soleus muscle: permissive effect of ATP.

1978 ◽  
Vol 235 (6) ◽  
pp. E606
Author(s):  
K T Yu ◽  
M K Gould
Keyword(s):  
Membrane Protein ◽  
Soleus Muscle ◽  
Specific Binding ◽  
High Capacity ◽  
Insulin Binding ◽  
High Affinity ◽  
Dependent Process ◽  
Xylose Uptake ◽  
High Affinity Site ◽  
Rat Soleus Muscle

The specific binding of 125I-insulin by rat soleus muscle was depressed when muscle ATP was depleted, either by prolonged anoxia or more rapidly with 2,4-dinitrophenol. Insulin binding was not eliminated in ATP-depleted muscle, but was reduced by 70--80%. Insulin binding by aerobic muscle could be resolved into two components; a high-affinity, low-capacity site (KD = 7.8 nM) and a low-affinity, high-capacity site (KD = 390 nM). The stimulatory effect of insulin on xylose uptake could be correlated with binding to the high-affinity site. These results indicate that there is some ATP-dependent process involved in the regulation of insulin binding by soleus muscle. It is suggested that this could be a phosphorylation-dephosphorylation system, acting either on the receptor itself or on some closely related membrane protein.

scholarly journals Tip Loci: Six Chlamydomonas Nuclear Suppressors That Permit the Translocation of Proteins with Mutant Thylakoid Signal Sequences

Genetics ◽  
1998 ◽  
Vol 149 (3) ◽  
pp. 1293-1301
Author(s):  
Karen K Bernd ◽  
Bruce D Kohorn
Keyword(s):  
Membrane Protein ◽  
Protein Translocation ◽  
Genetic Interaction ◽  
Signal Sequence ◽  
Cytochrome F ◽  
Signal Sequences ◽  
Photoautotrophic Growth ◽  
Thylakoid Protein ◽  
Allele Specific ◽  
Nuclear Loci

Abstract Mutations within the signal sequence of cytochrome f (cytf) in Chlamydomonas inhibit thylakoid membrane protein translocation and render cells nonphotosynthetic. Twenty-seven suppressors of the mutant signal sequences were selected for their ability to restore photoautotrophic growth and these describe six nuclear loci named tip1 through 6 for thylakoid insertion protein. The tip mutations restore the translocation of cytf and are not allele specific, as they suppress a number of different cytf signal sequence mutations. Tip5 and 2 may act early in cytf translocation, while Tip1, 3, 4, and 6 are engaged later. The tip mutations have no phenotype in the absence of a signal sequence mutation and there is genetic interaction between tip4, and tip5 suggesting an interaction of their encoded proteins. As there is overlap in the energetic, biochemical and genetic requirements for the translocation of nuclear and chloroplast-encoded thylakoid proteins, the tip mutations likely identify components of a general thylakoid protein translocation apparatus.

Moral reasoning is the process of asking moral questions and answering them

2019 ◽  
Vol 42 ◽  
Author(s):  
Mark Alfano
Keyword(s):  
Moral Reasoning ◽  
Dependent Process ◽  
Asking Questions ◽  
Path Dependent ◽  
Path Dependent Process ◽  
Moral Questions

Abstract Reasoning is the iterative, path-dependent process of asking questions and answering them. Moral reasoning is a species of such reasoning, so it is a matter of asking and answering moral questions, which requires both creativity and curiosity. As such, interventions and practices that help people ask more and better moral questions promise to improve moral reasoning.

TMCC3 localizes at the three-way junctions for the proper tubular network of the endoplasmic reticulum

2019 ◽  
Vol 476 (21) ◽  
pp. 3241-3260
Author(s):  
Sindhu Wisesa ◽  
Yasunori Yamamoto ◽  
Toshiaki Sakisaka
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Membrane Protein ◽  
Mammalian Cells ◽  
Coiled Coil ◽  
Transmembrane Domains ◽  
Domain Family ◽  
Coiled Coil Domain ◽  
U2os Cells ◽  
Er Membrane

The tubular network of the endoplasmic reticulum (ER) is formed by connecting ER tubules through three-way junctions. Two classes of the conserved ER membrane proteins, atlastins and lunapark, have been shown to reside at the three-way junctions so far and be involved in the generation and stabilization of the three-way junctions. In this study, we report TMCC3 (transmembrane and coiled-coil domain family 3), a member of the TEX28 family, as another ER membrane protein that resides at the three-way junctions in mammalian cells. When the TEX28 family members were transfected into U2OS cells, TMCC3 specifically localized at the three-way junctions in the peripheral ER. TMCC3 bound to atlastins through the C-terminal transmembrane domains. A TMCC3 mutant lacking the N-terminal coiled-coil domain abolished localization to the three-way junctions, suggesting that TMCC3 localized independently of binding to atlastins. TMCC3 knockdown caused a decrease in the number of three-way junctions and expansion of ER sheets, leading to a reduction of the tubular ER network in U2OS cells. The TMCC3 knockdown phenotype was partially rescued by the overexpression of atlastin-2, suggesting that TMCC3 knockdown would decrease the activity of atlastins. These results indicate that TMCC3 localizes at the three-way junctions for the proper tubular ER network.

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