Related Experiment Video
Updated: Jan 31, 2026
07:38
Milk Collection in the Rat Using Capillary Tubes and Estimation of Milk Fat Content by Creamatocrit
Published on: December 16, 2015
13.1K
Milk biosynthesis requires the Golgi cation exchanger TMEM165
Nathan A Snyder1, Mitchell V Palmer2, Timothy A Reinhardt3
1From the Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218 and.
The Journal of Biological Chemistry
|January 10, 2019
Summary
Transmembrane protein 165 (TMEM165) is essential for milk production in mammals. It maintains Golgi pH, ensuring proper lactose synthesis and offspring growth.
Area of Science:
- Cell Biology
- Mammalian Physiology
- Biochemistry
Background:
- Lactose biosynthesis in the Golgi complex produces H+, potentially disrupting pH homeostasis.
- A mechanism for maintaining physiological pH within the Golgi during milk production is unknown.
Purpose of the Study:
- To investigate the role of the H+/Ca2+/Mn2+ exchanger TMEM165 in mammalian milk production.
- To determine if TMEM165 is crucial for lactose biosynthesis and offspring development.
Main Methods:
- Conditional, tissue-specific knockout mice were utilized.
- Immunostaining and biochemical assays were performed.
- Lactating mammary glands and milk composition were analyzed.
Main Results:
- TMEM165 deficiency impaired lactose biosynthesis and pup growth rates.
- Milk from deficient mice showed increased fat and protein, with reduced Ca2+ and Mn2+ levels.
- TMEM165 appears to facilitate Ca2+ and Mn2+ transport into the Golgi in exchange for H+.
Conclusions:
- TMEM165 is critical for maintaining Golgi cation and pH homeostasis during lactation.
- This homeostasis is vital for the function of lactose synthase and other glycosyltransferases.
- TMEM165 plays a key role in normal milk production and offspring nutrition.
Related Concept Videos
01:49Golgi Apparatus
101.7K
As they leave the Endoplasmic Reticulum (ER), properly folded and assembled proteins are selectively packaged into vesicles. These vesicles are transported by microtubule-based motor proteins and fuse together to form vesicular tubular clusters, subsequently arriving at the Golgi apparatus, a eukaryotic endomembrane organelle that often has a distinctive ribbon-like appearance.
101.7K
01:09Golgi Apparatus
21.9K
Properly folded and assembled proteins are selectively packaged into vesicles that exit the ER. Motor proteins transport these vesicles to the Golgi apparatus for adding modifications that make these proteins functional at their destination.
The Golgi apparatus is a eukaryotic organelle that has a distinctive ribbon-like appearance. It is a primary sorting and dispatch station for cargo arriving from the ER. Newly arriving vesicles enter the cis face of the Golgi, closest to the ER, and are...
The Golgi apparatus is a eukaryotic organelle that has a distinctive ribbon-like appearance. It is a primary sorting and dispatch station for cargo arriving from the ER. Newly arriving vesicles enter the cis face of the Golgi, closest to the ER, and are...
21.9K
01:24Biosynthesis in Bacteria
662
Biosynthesis in bacteria is a fundamental anabolic process that generates essential macromolecules, including proteins, nucleic acids, lipids, and polysaccharides. These macromolecules are critical for cellular growth, replication, and function. The process is tightly regulated and energetically linked to catabolic pathways to ensure optimal resource utilization.Biosynthetic pathways begin with precursor metabolites such as pyruvate, acetyl-CoA, and glucose-6-phosphate derived from glycolysis,...
662
01:26Biosynthesis of Polysaccharides
626
Polysaccharides such as glycogen and starch are synthesized from nucleoside diphosphate sugars, primarily uridine diphosphate glucose (UDPG) and adenosine diphosphate glucose (ADPG). These activated glucose donors act as key intermediates in carbohydrate metabolism and biosynthesis. UDPG primarily involves glycogen synthesis in animals and many bacteria, while ADPG plays a fundamental role in starch synthesis in plants and certain bacteria.UDPG is formed when glucose-1-phosphate reacts with...
626
01:29Biosynthesis of Lipids
580
Microbial membranes exhibit remarkable diversity in lipid composition, reflecting evolutionary adaptations to various environmental conditions. The three domains of life—Bacteria, Archaea, and Eukarya—synthesize membrane lipids through distinct biosynthetic pathways, leading to fundamental structural differences that impact membrane stability, function, and adaptability.Fatty Acid-Based Lipids in Bacteria and EukaryaBacteria and eukaryotes share a common fatty acid biosynthesis...
580
02:06Social Exchange Theory
40.8K
We have discussed why we form relationships, what attracts us to others, and different types of love. But what determines whether we are satisfied with and stay in a relationship? One theory that provides an explanation is social exchange theory. According to social exchange theory, we act as naïve economists in keeping a tally of the ratio of costs and benefits of forming and maintaining a relationship with others (Rusbult & Van Lange, 2003).
40.8K