Distribution of Na+, K(+)-ATPase alpha-subunit isoforms in rat pituitary
P M Rowe1, W T Link, C P Osborn
1Laboratory of Neurochemistry, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland 20892.
Journal of Neurochemistry
|September 1, 1991
Summary
This study maps the distribution of sodium-potassium pump (Na+,K(+)-ATPase) alpha-subunit isoforms in rat pituitary glands. Different isoforms are found in the neural, anterior, and intermediate lobes, revealing specific regional expression patterns.
Area of Science:
- Neuroscience
- Cell Biology
- Biochemistry
Background:
- The sodium-potassium pump (Na+,K(+)-ATPase) is crucial for maintaining cellular homeostasis.
- Alpha-subunit isoforms of Na+,K(+)-ATPase exhibit distinct tissue-specific expression patterns and functional roles.
- Understanding isoform distribution in the pituitary gland is essential for elucidating its neuroendocrine functions.
Purpose of the Study:
- To determine the precise distribution of alpha-subunit isoforms (alpha 1, alpha 2, and alpha 3) of the Na+,K(+)-ATPase in different regions of the rat pituitary gland.
- To correlate the presence of specific isoforms with known Na+,K(+)-ATPase activity in the pituitary.
Main Methods:
- Immunoblotting techniques were employed to detect the presence of Na+,K(+)-ATPase alpha-subunit isoforms.
- Immunohistochemistry was utilized to visualize the spatial localization of these isoforms within the pituitary gland.
- Analysis focused on the neural, anterior, and intermediate lobes of the rat pituitary.
Main Results:
- All three alpha-subunit isoforms (alpha 1, alpha 2, alpha 3) were detected in the neural lobe.
- The anterior lobe showed immunoreactivity for only the alpha 1 and alpha 2 isoforms.
- The intermediate lobe primarily exhibited alpha 1 isoform immunoreactivity, with scattered cells strongly expressing all three isoforms.
Conclusions:
- The differential expression of Na+,K(+)-ATPase alpha-subunit isoforms in the rat pituitary suggests region-specific functions.
- The presence of alpha 2 and alpha 3 subunits in the neural lobe aligns with previously reported ouabain-inhibitable Na+,K(+)-ATPase activity.
- This study provides a detailed map of Na+,K(+)-ATPase isoform distribution, contributing to a better understanding of pituitary physiology.
More Related Videos
08:24Nitrogen Cavitation and Differential Centrifugation Allows for Monitoring the Distribution of Peripheral Membrane Proteins in Cultured Cells
Published on: August 18, 2017
07:13A Simple and Reproducible Method to Prepare Membrane Samples from Freshly Isolated Rat Brain Microvessels
Published on: May 7, 2018
Related Concept Videos
01:48ATP Synthase: Mechanism
In animals, the mitochondrial F1F0 ATP synthase is the key protein that synthesizes ATP molecules through a complex catalytic mechanism. While the nuclear genome encodes the majority of ATP synthase subunits, the mitochondrial genome encodes some of the enzyme's most critical components. The formation of this multi-subunit enzyme is a complex multi-step process regulated at the level of transcription, translation, and assembly. Defects in one or more of these steps can result in decreased ATP...
01:18ATP Synthase: Structure
ATP synthase or ATPase is among the most conserved proteins found in bacteria, mammals, and plants. This enzyme can catalyze a forward reaction in response to the electrochemical gradient, producing ATP from ADP and inorganic phosphate. ATP synthase can also work in a reverse direction by hydrolyzing ATP and generating an electrochemical gradient. Different forms of ATP synthases have evolved special features to meet the specific demands of the cell. Based on their specific feature, ATP...
01:34ATP Driven Pumps II: P-type Pumps
The P-type pumps are a large family of integral membrane transporter ATPases. They are divided into five major types based on substrate specificity, from I to V.
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
A typical P-type pump has three cytosolic domains: nucleotide-binding (N), phosphorylation (P), and activator (A) domains. These domains are connected to the membrane-spanning helices by short amino acid segments. ATP hydrolysis and covalent phosphoenzyme intermediate formation are crucial parts of the catalytic cycle. At the highly...
01:30ATP Driven Pumps III: V-type Pumps
V-type pumps are ATP-driven pumps found in the vacuolar membranes of plants, yeast, endosomal and lysosomal membranes of animal cells, plasma membranes of a few specialized eukaryotic cells, and some prokaryotes. They are also known as the V1Vo-ATPase, that couple ATP hydrolysis to transport protons against a concentration gradient.
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
The peripheral or cytosolic V1 domain with eight subunits is involved in ATP hydrolysis. The integral or transmembrane V0 domain containing at least five subunits...
01:22Activation and Inactivation of G Proteins
Heterotrimeric G proteins are guanine nucleotide-binding proteins. As the name suggests, heterotrimeric G proteins are composed of three subunits: alpha, beta, and gamma. They remain GDP-bound or GTP-bound inside the cells and switch between inactive/active states. The Gα subunit possesses the nucleotide-binding pocket that binds guanine nucleotides and switches between GDP or GTP-bound states. In contrast, the Gꞵ and Gγ subunits are always bound together with high affinity and are together...