Aldosterone signaling pathway across the nuclear envelope.
نویسندگان
چکیده
We describe the route by which aldosterone-triggered macromolecules enter and exit the cell nucleus of Xenopus laevis oocyte. Oocytes were microinjected with 50 fmol aldosterone and then enucleated 2-30 min after injection. After isolation, nuclear envelope electrical resistance (NEER) was measured in the intact cell nuclei by using the nuclear hourglass technique. We observed three NEER stages: an early peak 2 min after injection, a sustained depression after 5-15 min, and a final late peak 20 min after injection. Because NEER reflects the passive electrical permeability of nuclear pores, we investigated with atomic force microscopy aldosterone-induced conformational changes of individual nuclear pore complexes (NPCs). At the early peak we observed small ( congruent with 100 kDa) molecules (flags) attached to the NPC surface. At the sustained depression NPCs were found free of flags. At the late peak large ( congruent with 800 kDa) molecules (plugs) were detected inside the central channels. Ribonuclease or actinomycin D treatment prevented the late NEER peak. Coinjection of aldosterone (50 fmol) and its competitive inhibitor spironolactone (500 fmol) eliminated the electrical changes as well as flag and plug formation. We conclude: (i) The genomic response of aldosterone can be electrically measured in intact oocyte nuclei. (ii) Flags represent aldosterone receptors on their way into the cell nucleus whereas plugs represent ribonucleoproteins carrying aldosterone-induced mRNA from the nucleoplasm into the cytoplasm. (iii) Because plugs can be mechanically harvested with the atomic force microscopy stylus, oocytes could serve as a bioassay system for identifying aldosterone-induced early genes.
منابع مشابه
Anti-diabetic effect of loganin by inhibiting FOXO1 nuclear translocation via PI3K/Akt signaling pathway in INS-1 cell
Objective(s): JiangTangXiaoKe (JTXK) granule, a Chinese traditional herbal formula, has been clinically used and demonstrated to be beneficial in controlling high glucose and to relieve the symptoms of Type 2 diabetes mellitus patients for decades. In this study, we explored how loganin, one of the components in JTXK granule, mediated the anti-diabetic effect.Materials and Methods: We generate...
متن کاملA Novel Receptor-Mediated Nuclear Protein Import Pathway
Targeting of most nuclear proteins to the cell nucleus is initiated by interaction between the classical nuclear localization signals (NLSs) contained within them and the importin NLS receptor complex. We have recently delineated a novel 38 amino acid transport signal in the hnRNP A1 protein, termed M9, which confers bidirectional transport across the nuclear envelope. We show here that M9-medi...
متن کاملProtosappanin A protects against atherosclerosis via anti- hyperlipidemia, anti-inflammation and NF-κB signaling pathway in hyperlipidemic rabbits
Objective(s): Protosappanin A (PrA) is an effective and major ingredient of Caesalpinia sappan L. The current study was aimed to explore the effect of PrA on atherosclerosis (AS). Materials and Methods: Firstly, the experimental model of AS was established in rabbits by two-month feeding of high fat diet. Then, the rabbits were randomly divided into five groups and treated with continuous high ...
متن کاملElectroacupuncture attenuates chronic fibromyalgia pain through the phosphorylated phosphoinositide 3-kinase signaling pathway in the mouse brain
Objective(s): Fibromyalgia (FM) is a central nervous system disorder characterized by widespread mechanical hyperalgesia due to unknown mechanisms. Several inflammatory mediators, such as interleukin-1 (IL-1), IL-6, IL-8, and tumor necrosis factor, are increased in the serum of FM patients. Although medications including pregabalin, duloxetine, and milnacipran are used...
متن کاملGenomic and Non-genomic Aldosterone
Steroid hormones are lipophilic hormones based on the cholesterol molecule. Steroid hormones include the sex hormones estrogen, progesterone, and testosterone; glucocorticoids mainly cortisol in human; and mineralocorticoids. The main mammalian mineralocorticoid is aldosterone. Steroid and steroid-like hormones such as vitamin D and thyroid hormone are lipophilic and exert their predominant act...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Proceedings of the National Academy of Sciences of the United States of America
دوره 99 10 شماره
صفحات -
تاریخ انتشار 2002