scholarly journals ATG8-interacting (ATI) 1 and 2 define a plant starvation-induced ER-phagy pathway and serve as MSBP1 (MAPR5) cargo-receptors

2020 ◽  
Author(s):  
Jian Wu ◽  
Simon Michaeli ◽  
Gad Galili ◽  
Hadas Peled-Zehavi
Keyword(s):  
Er Stress ◽  
Interacting Proteins ◽  
Tor Signaling ◽  
Interacting Protein ◽  
Selective Autophagy ◽  
Unicellular Algae ◽  
Steroid Binding ◽  
Energy Deprivation ◽  
Steroid Binding Protein

AbstractER-phagy, the selective autophagy of endoplasmic reticulum (ER) components, is known to operate in eukaryotes from yeast and unicellular algae to animals and plants. Thus far, only ER-stress derived ER-phagy was reported and analyzed in plants. In this study we characterize an ER-phagy pathway in Arabidopsis thaliana that is triggered by dark-induced starvation and not by ER-stress. This pathway is defined by the previously reported ATG8-interacting proteins, ATI1 and ATI2 and is regulated by the TOR signaling pathway. We further identified ER-localized Membrane Steroid Binding Protein 1 (MSBP1) as an ATI1 and 2 interacting protein and an autophagy cargo, and show that ATI1 and 2 serve as its cargo receptors. Together, these findings expand our knowledge on plants responses during energy deprivation and highlight the role of this special type of ER-phagy in this process.

Plasma membrane proteome analysis identifies a role of barley membrane steroid binding protein in root architecture response to salinity

2018 ◽  
Vol 41 (6) ◽  
pp. 1311-1330 ◽  
Author(s):  
Katja Witzel ◽  
Andrea Matros ◽  
Anders L.B. Møller ◽  
Eswarayya Ramireddy ◽  
Christine Finnie ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Root Architecture ◽  
Binding Protein ◽  
Proteome Analysis ◽  
Membrane Proteome ◽  
Steroid Binding ◽  
Steroid Binding Protein

scholarly journals Biochemistry, pharmacology and physiological role of sex hormone binding globulin

2018 ◽  
Vol 49 (3) ◽  
pp. 189
Author(s):  
D. KOURETAS (Δ. ΚΟΥΡΕΤΑΣ) ◽  
V. LALIOTIS (Β. ΛΑΛΙΩΤΗΣ) ◽  
O. ANTONOGLOU (Ο. ΑΝΤΩΝΟΓΛΟΥ)
Keyword(s):  
Sex Steroids ◽  
Physiological Role ◽  
Sex Hormone Binding Globulin ◽  
Target Cells ◽  
Hormone Binding ◽  
High Affinity ◽  
Dimeric Protein ◽  
Steroid Binding ◽  
Steroid Binding Protein

Sex steroid binding protein (SBP) is a plasma protein that specifically binds sex steroids with high affinity. It is synthesized in the liver and circulates in the plasma of many species including human, monkey, cattle, dog, cat and others. SBP is a dimeric protein with a Mr ranging between 84-9Θ KDa and binds one steroid molecule per dimer. Its expression is regulated by many hormones and estradiol promotes while testosterone inhibits its expression. Its physiological role is not known completely, but it is likely to control at least the bioavailable levels of circulating steroids. Experimental evidence from our laboratory and others supports the dogma that non-bound steroids are free to enter the target cells and act. After the discovery of SBP-membrane receptor, it seems that SBP serves also other biological role except that of binding steroids. All recent reports are discussed.

A 63-kDa protein with androgen-binding activity is not from the androgen receptor

1991 ◽  
Vol 69 (10-11) ◽  
pp. 695-701 ◽  
Author(s):  
Klaus Wrogemann ◽  
Gary Podolsky ◽  
Jin Gu ◽  
Eduardo Rosenmann
Keyword(s):  
Androgen Receptor ◽  
Binding Activity ◽  
Water Soluble ◽  
Two Dimensional ◽  
Testicular Feminization ◽  
Steroid Binding ◽  
Androgen Binding ◽  
New Protein ◽  
Steroid Binding Protein

We have found a new protein in the heart of rat and mice that can be selectively and covalently labelled with the synthetic androgen analog mibolerone. Binding is specific as it can be displaced by excess radioinert ligand. The protein is prominently expressed in liver, kidney, and heart, but not in skeletal muscle. It is water soluble and found in the cytosol. Under denaturing conditions it has a molecular weight of 63 000 and appears on two-dimensional gels with an isoelectric point of 6.3. The protein's affinity for androgen is lower than that of the androgen receptor and it is about 100-fold more abundant than the receptor in the heart. Expression of the protein is not induced by androgen. The presence of this protein in testicular feminization (tfm) mice with a genetical defect of the androgen receptor rules out that it is the androgen receptor or a portion thereof. The biological role of this protein is not yet known.Key words: androgen, androgen receptor, heart, photolysis, steroid binding protein.

scholarly journals The Oncogenic Potential of TCTEX1D4 is Modulated by the Phosphoprotein Phosphatase PP1

2021 ◽  
Author(s):  
Juliana Felgueiras ◽  
Luís Sousa ◽  
Ana Luísa Luísa Teixeira ◽  
Bárbara Regadas ◽  
Luís Korrodi-Gregório ◽  
...  
Keyword(s):  
Protein Phosphatase ◽  
Protein Phosphatase 1 ◽  
Human Prostate ◽  
Interacting Proteins ◽  
Interacting Protein ◽  
Oncogenic Potential ◽  
Regulatory Subunits ◽  
Prostate Tumorigenesis ◽  
Cellular Events

Abstract Protein phosphatase 1 (PP1) regulates several cellular events via interaction with multiple regulatory subunits. The human prostate proteome includes various PP1-interacting proteins; however, a very limited number of interactions is yet characterized and their role in prostate tumorigenesis remains poorly understood. Tctex1 domain-containing protein 4 (TCTEX1D4) was previously identified as a PP1-interacting protein, but its function, as well as the relevance of its interaction with PP1, are virtually unknown. In this study we addressed the role of the PP1/TCTEX1D4 complex in prostate tumorigenesis. We found distinct expression levels and subcellular distributions for TCTEX1D4 and PP1γ in human prostate epithelial normal-like and malignant cells. Moreover, we showed that TCTEX1D4 participates in the regulation of cell proliferation and modulation of microRNAs expression and that its interaction with PP1 controls its function. Taken together, our study provides first evidence for the involvement of the PP1/TCTEX1D4 complex in prostate tumorigenesis.

The role of ER stress for the pathogenesis of SCA3 in primary cell culture experiment

2007 ◽  
Vol 34 (S 2) ◽  
Author(s):  
C Funke ◽  
J Hübener ◽  
H Wolburg ◽  
T Schmidt ◽  
H Toresson ◽  
...  
Keyword(s):  
Cell Culture ◽  
Er Stress ◽  
Primary Cell Culture ◽  
Primary Cell ◽  
Culture Experiment ◽  
Cell Culture Experiment

MEASUREMENT OF STEROID BINDING PROTEINS

1970 ◽  
Vol 65 (1_Suppl) ◽  
pp. S104-S121 ◽  
Author(s):  
E. E. Baulieu ◽  
J. P. Raynaud ◽  
E. Milgrom
Keyword(s):  
Kinetic Parameters ◽  
Binding Proteins ◽  
Binding Specificity ◽  
Binding Parameters ◽  
Target Organs ◽  
Biological Mixtures ◽  
Steroid Binding Proteins ◽  
Steroid Binding ◽  
Steroid Binding Protein

ABSTRACT A brief review of the characteristics of steroid binding proteins found in the plasma and in some target organs is presented, followed by some general remarks on binding »specificity« and binding parameters. Useful techniques for measuring binding parameters at equilibrium are reported, both those which keep the equilibrium intact and those which implicate its disruption. A concept is developed according to which the determination of a specific steroid binding protein is based on the »differential dissociation« of the several steroid binding complexes present in most biological mixtures. Methods which allow determination of the kinetic parameters of the binding systems are also presented. Various representations of the binding and therefore different modes of graphic representation and calculation are discussed, including the recent »proportion graph« method.

Foetal steroid binding protein in British and Japanese women

1987 ◽  
Vol 114 (4) ◽  
pp. 584-588 ◽  
Author(s):  
M. Jawed Iqbal ◽  
Alastair Forbes ◽  
Mark L. Wilkinson ◽  
John W. Moore ◽  
Roger Williams ◽  
...  
Keyword(s):  
Ovarian Function ◽  
Binding Protein ◽  
Premenopausal Women ◽  
Japanese Women ◽  
Sex Hormone Binding Globulin ◽  
Partial Purification ◽  
Enzyme Linked Immunosorbent Assay ◽  
Binding Characteristics ◽  
Steroid Binding ◽  
Steroid Binding Protein

Abstract. In order to examine the newly-discovered sex-steroid binding protein, foetal steroid binding protein (FSBP) in different populations, its binding characteristics and its level were studied by two-tier column ligand binding assay and enzyme-linked immunosorbent assay (ELISA) respectively. In 10 Japanese premenopausal women, analysis of 5α-dihydrotestosterone (DHT) binding in the Cibacron Blue 3GA-Sepharose 6B portion of the column showed a rising plateau pattern with a mean maximum binding of 31.1 ± 7.41%, whereas of 9 similar British women, 8 displayed unsaturable, non-cooperative binding of 11.6 ± 8.22% (P < 0.01). After partial purification of FSBP in these samples, the protein exhibited saturable binding kinetics, median binding 25 (interquartiles 23–34) and 19 (13–25) nmol DHT/l in Japanese and British women, respectively (P < 0.05). By analyzing FSBP by ELISA in 56 Japanese (45 premenopausal) and 59 British (25 premenopausal) women, higher levels were obtained in the whole Japanese group (P = 0.0016) and in the premenopausal Japanese women (P = 0.018) than in their British counterparts. In both nationalities, FSBP levels were higher in premenopausal women, and there was a significant negative correlation of FSBP with age in both populations, particularly in postmenopausal women. FSBP levels did not correlate with weight, parity, sex hormone binding globulin or albumin levels. The influence of FSBP on free steroid levels remains unclear, but some relationship with ovarian function seems a possibility.

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