scholarly journals Intracellular localization of relaxin in membrane-bound granules in the pregnant rat luteal cell

1984 ◽  
Vol 30 (3) ◽  
pp. 753-762 ◽  
Author(s):  
P. A. Fields
Keyword(s):  
Intracellular Localization ◽  
Luteal Cell ◽  
Pregnant Rat ◽  
Membrane Bound

Regulation of Luteal Cell Lipoprotein Receptors, Sterol Contents, and Steroidogenesis by Estradiol in the Pregnant Rat*

Endocrinology ◽  
1984 ◽  
Vol 114 (2) ◽  
pp. 609-617 ◽  
Author(s):  
GEULA GIBORI ◽  
Y. -D. IDA CHEN ◽  
IQBAL KHAN ◽  
SALMAN AZHAR ◽  
G. M. REAVEN
Keyword(s):  
Luteal Cell ◽  
Lipoprotein Receptors ◽  
Pregnant Rat

scholarly journals Gonadotropin Dependent Neuregulin1 Signaling Regulates Luteal Cell Survival

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A766-A767
Author(s):  
Jennifer Jones ◽  
Saswati Banerjee ◽  
Winston E Thompson ◽  
Indrajit Chowdhury
Keyword(s):  
Signaling Pathway ◽  
First Trimester ◽  
Immunoblot Analysis ◽  
National Institutes Of Health ◽  
Luteal Cell ◽  
Dependent Manner ◽  
Experimental Conditions ◽  
Pregnant Rat ◽  
Factor Α

Abstract The formation of a functional corpus luteum (CL) is an absolute requirement for reproductive success and is induced by the mid-cycle surge of luteinizing hormone (LH). The CL is a transient ovarian endocrine structure that maintains pregnancy in primate during the first trimester and in rodents during the entire pregnancy by producing steroid hormone progesterone (P4). CL growth and differentiation are tightly regulated by both survival and cell death signals, including endocrine (LH), intra-ovarian regulators, and cell-cell interactions. Neuregulin-1 (NRG1) is a member of the epidermal growth factor-like factor family that mediates it’s effect through the erythroblastoma (ErbB) family. However, the detailed mechanisms associated with the interplay of NRG1 and its receptors in CL function is not known. Therefore, we examined the role and action of NRG1 and its receptors in the gonadotropin signaling pathway that impacts CL functions. Immunocolocalization of NRG1 and ErbB2/3 in pregnant rat CL on day 14 and 21 suggest that both NRG1 and ErbB2/3 are differentially expressed in CL. Moreover, both NRG1 and ErbB2/3 are highly expressed in rat CL on day 14 compared to day 21. Furthermore, in vitro studies revealed that rat luteal cells (LCs) treated with exogenous tumor necrosis factor-α (TNFα, an inflammatory cytokine) promoted apoptosis in LCs in a dose and time-dependent manner. However, the effects of TNFα was attenuated in presence of exogenous NRG1. Under these experimental conditions, immunoblot analysis indicated that exogenous TNFα treatment in the presence of NRG1 inhibits apoptosis through increased levels of the anti-apoptotic proteins Bcl2 and Bclxl, and activation of ErbB2-ErbB3-PI3K-Akt signaling pathway. Collectively, these studies provide new insights on the NRG1-mediated anti-apoptotic mechanism in LCs through ErbB3-ErbB2-PI3K-Akt→Bcl/Bcl-xL pathway and may have important clinical implications. Acknowledgements: This study was supported in part by National Institutes of Health Grants 1 SC1 GM130544-01A1, 1SC3GM113751 and G12RR03034. This research was conducted in a facility constructed with support from the Research Facilities Improvement Grant C06RR018386 from the National Institutes of Health National Center for Research Resources.

scholarly journals Programmable Sequences of Reflectin Proteins Provides Evidence for Their Evolution Processes, Tunable Intracellular Localization and Interaction with Cytoskeleton

2021 ◽  
Author(s):  
Junyi Song ◽  
Liu Chuanyang ◽  
Baoshan Li ◽  
Liangcheng Liu ◽  
LIng Zeng ◽  
...  
Keyword(s):  
Phase Separation ◽  
Spatial Organization ◽  
Dynamic Performance ◽  
Intracellular Localization ◽  
Evolutionary Relationship ◽  
Biochemical Properties ◽  
Membrane Bound ◽  
Phase Out ◽  
Intracellular Milieu ◽  
Liquid Liquid Phase Separation

Reflectins are membrane-bound proteins located in cephalopods iridocytes, with repeated canonical domains interspersed with cationic linkers. Scientists keep curious about their evolutionary processes, biochemical properties and intracellular functions. Here, by introducing reflectin A1, A2, B1 and C into HEK-293T cells, these proteins were found to phase out from the crowded intracellular milieu, with distinguished localization preferences. Inspired by their programmable block sequences, several truncated reflectin A1 (RfA1) peptides based on repetition of reflectin motifs were designed and transfected into cells. An obvious cyto-/nucleo-plasmic localization preference was once again observed. The dynamic performance of RfA1 derivatives and their analogic behavior between different reflectins suggest a conceivable evolutionary relationship among reflectin proteins. Additionally, a proteomic survey identified biochemical partners which contribute to the phase separation and intracellular localization of RfA1 and its truncations, as well as the close collaboration between RfA1 and the cytoskeleton systems. These findings indicate that liquid-liquid phase separation could be the fundamental mode for reflectins to achieve spatial organization, to cooperate with cytoskeleton during the regulation of reflective coloration. On the other hand, the dynamic behaviors of RfA1 derivatives strongly recommended themselves as programmable molecular tools.

scholarly journals A conformational switch driven by phosphorylation regulates Ykt6 activity in macroautophagy

2020 ◽  
Author(s):  
Kaitlyn McGrath ◽  
Mykola Dergai ◽  
Shivani Agarwal ◽  
Daayun Chung ◽  
Damian B. van Rossum ◽  
...  
Keyword(s):  
Membrane Fusion ◽  
Conformational Change ◽  
Mammalian Cells ◽  
Intracellular Localization ◽  
Phosphorylation Site ◽  
Structural Modeling ◽  
Snare Proteins ◽  
Conformational Switch ◽  
Membrane Bound ◽  
Open Membrane

ABSTRACTMembrane fusion, an essential process in all eukaryotes, is driven by SNARE proteins. Ykt6 is an essential SNARE that plays critical roles throughout the secretory, endocytic, and autophagy pathways. Ykt6 activity is thought to be regulated by a conformational change from a closed cytosolic form to an open membrane-bound form, yet the mechanism that regulates this transition is unknown. Through genetic, pharmacologic, and structural modeling approaches in mammalian cells, we found that phosphorylation regulates Ykt6 conversion from a closed to an open state. The phosphorylation site we identified is highly conserved in evolution and is regulated by the Ca2+-dependent phosphatase, calcineurin. We found that phosphorylation is a key determinant for intracellular localization of Ykt6 and its function in macroautophagy. Our studies reveal a novel mechanism by which Ykt6 conformation and activity is regulated by Ca2+ signaling with implications in Parkinson’s Disease in which Ykt6 has been shown to play a role.

Membrane assembly: movement of phosphatidylserine between the cytoplasmic and outer membranes of Escherichia coli

1982 ◽  
Vol 152 (3) ◽  
pp. 1033-1041
Author(s):  
K E Langley ◽  
E Hawrot ◽  
E P Kennedy
Keyword(s):  
Escherichia Coli ◽  
Outer Membrane ◽  
Sucrose Gradient ◽  
Intracellular Localization ◽  
Temperature Sensitive ◽  
Inner Membrane ◽  
E Coli ◽  
Outer Membranes ◽  
Membrane Bound ◽  
Gradient Fractionation

Phosphatidylserine, normally a trace phospholipid in Escherichia coli, accumulates at high levels in temperature-sensitive phosphatidylserine decarboxylase mutants at nonpermissive temperatures. The intracellular localization of this phospholipid has now been determined. All of the accumulated phosphatidylserine is membrane bound and is distributed about equally between the inner and outer membrane fractions of E. coli as determined by isopycnic sucrose gradient fractionation. Phosphatidylserine is therefore effectively translocated from the inner to the outer membrane. Furthermore, this movement is bidirectional. Outer membrane phosphatidylserine can return to the inner membrane, as shown by the complete conversion of accumulated radioactive phosphatidylserine to phosphatidylethanolamine by inner membrane phosphatidylserine decarboxylase during chase periods. Pulse-chase experiments indicated the newly made phosphatidylserine appears first in the inner membrane and then equilibrates between the inner and outer membranes with a half-time of 12 to 13 min.

Two polyclonal antisera to rat luteal LH/CG receptor with different ligand binding inhibition and immunohistochemical receptor detection capabilities

1991 ◽  
Vol 125 (3) ◽  
pp. 305-312 ◽  
Author(s):  
Jouni T. Lakkakorpi ◽  
Kari P. Keinänen ◽  
Hannu J. Rajaniemi
Keyword(s):  
Luteal Cell ◽  
Complex Method ◽  
Dependent Manner ◽  
Hormone Binding ◽  
Sds Page ◽  
Antibody Titres ◽  
Membrane Bound ◽  
Polyclonal Antisera ◽  
Detection Capabilities ◽  
Reduced Forms

Abstract. Polyclonal antisera to a SDS-denatured and partially renatured rat luteal 90 K LH/CG receptor were raised in rabbits, characterized, and their applicability for immunohistochemical location of the receptor examined. The LH/CG receptor was purified by hCG-affinity chromatography and subjected either to a preparative SDS-PAGE or Western blotting. Gel slices containing the SDS-denatured or nitrocellulose strips containing the renatured 90 K LH/CG receptor were used for immunization. The antisera, termed ARS-2 and ARS-3, respectively, possessed similar antibody titres. Both antisera were able to recognize the native, SDS-denatured, and SDS-denatured and reduced forms of the LH/CG receptor on dot blots, but only ARS-3 contained antibodies to the hormone binding site or a region near to it, as it was able to inhibit the hCG binding to the membrane-bound LH/CG receptor in a dilution-dependent manner. Both antisera recognized the receptor-hCG complex, but ARS-2 stained the complex with about 50% less intensity than the free receptor. ARS-3 located the LH/CG receptor distinctly on the luteal cell surfaces in immunohistochemical staining with peroxidase antiperoxidase complex method, but ARS-2, although it possessed similar antibody titre, revealed negligible staining. Thus, the antisera readily recognize the native receptor, but differ in their capability for inhibiting hormone binding. Only ARS-3, produced against the renatured receptor, contains sufficient amounts of antibodies capable of recognizing free and occupied receptors in immunohistochemistry.

scholarly journals Relationships between levels of membrane-bound glucuronidase and the associated protein egasyn in mouse tissues.

1977 ◽  
Vol 73 (3) ◽  
pp. 728-735 ◽  
Author(s):  
A J Lusis ◽  
K Paigen
Keyword(s):  
Endoplasmic Reticulum ◽  
Postnatal Development ◽  
Intracellular Localization ◽  
Adult Tissues ◽  
Mouse Tissues ◽  
Membrane Bound ◽  
The Relationship

Mouse beta-glucuronidase has a dual intracellular localization, being present in both endoplasmic reticulum and lysosomes of several tissues. Previous studies demonstrated that the protein egasyn is complexed with microsomal but not lysosomal glucuronidase and that a mutant lacking egasyn is deficient in microsomal, but not lysosomal, glucuronidase. By means of a recently developed radioimmunoassay for egasyn, the relationship between microsomal glucuronidase levels and egasyn levels has been examined in various adult tissues, during postnatal development in liver, and after androgen induction of glucuronidase in kidney. The results indicate that the relative availability of egasyn determines the balance between glucuronidase incorporation into membranes and that into lysosomes.

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