Plasma Membrane Markers

Plasma Membrane Markers and Applications | Plasma Membrane Damage, Repair, and Role in Disease Pathology

What is the Plasma Membrane?

The plasma membrane is a selectively permeable lipid bilayer that separates the cytoplasm and intracellular components from the extracellular environment of a cell. It is a highly dynamic structure comprised of lipids and proteins, responsive to extracellular signals, like cytokines, hormones, and ions, resulting in intracellular signaling cascades. Movement of substances across the plasma membrane occurs via passive or active transport, the latter of which requires the expenditure of energy. Smaller molecules can cross the cell membrane by passive diffusion whereas larger, more polar molecules generally require active transporter-mediated entry. The plasma membrane also serves as the attachment point for the intracellular cytoskeleton, which helps to determine cell shape and motility.

Plasma Membrane Markers and Applications

Plasma Membrane Lipids

The phospholipid bilayer consists of two layers of phospholipids with the hydrophilic heads facing the extra- and intracellular environments and hydrophobic tails in the middle. In addition to phospholipids (e.g. phosphatidylserine (PtdSer), phosphatidylcholine (PtdCho)), other lipids, such as sphingolipids (e.g. sphingomyelin (SM)) and cholesterol are abundant in the plasma membrane. Lipids are essential for cell membrane energy storage, compartmentalization, membrane fluidity, and signaling.

Plasma Membrane Proteins

Common types of plasma membrane proteins include pumps and transporters, enzymes, receptors, and anchors. For example, G-protein coupled receptors (GPCRs) are a large family of receptors that convert extracellular messages into intracellular signaling cascades. The GPCR family of proteins includes important cytokine and chemokine receptors responsible for cell trafficking, like CCR7 and CXCR4. Na⁺/K⁺ ATPase and Pma1 are two common membrane ATPase pumps that have traditionally served as general plasma membrane markers.

Plasma membrane proteins also serve as drug candidate targets for the many pathologies associated with dysfunctional membrane proteins. Potential therapeutics can affect the protein function by blocking transport or inhibiting ligand binding, for example, resulting in cellular signaling modifications.

Antibodies to markers for the plasma membrane can be used in a wide range of applications including immunocytochemistry (ICC)/immunofluorescence (IF), immunohistochemistry (IHC), western blot, ELISA, flow cytometry, and immunoprecipitation (IP).

Common Plasma Membrane Markers and Function

Note: The markers listed in the table is not an exhaustive list of all plasma membrane markers.

Plasma Membrane Damage, Repair, and Role in Disease Pathology

Plasma Membrane Damage and Repair

Insults to the plasma membrane can result from a variety of different causes including mechanical, chemical, microbial, immune, or intracellular mechanisms. A physical breach or chemical disruption can induce plasma membrane damage and leave the cell susceptible to further injury. Chemical damage through radiation or reactive oxygen species (ROS) can make mechanical stress like nanoruptures and pore formation more likely.

Many cell death pathways such as apoptosis, necroptosis, and ferroptosis are characterized, in part, by plasma membrane damage. One of the earliest signs of apoptosis is transition of PtdSer from the inner membrane to the outer membrane. Bio-Techne’s Polarity Sensitive Indicator of Viability and Apoptosis (pSIVA) contains an Annexin-based probe to detect apoptosis by PtdSer externalization, both irreversible and transient. Our pSIVA Apoptosis Detection Kits are suitable for multiple applications including flow cytometry and ICC/IF.

The plasma membrane follows four stages of repair after a physical breach:

1. Sealing off a physical breach via various mechanisms such as exocytosis, endocytosis, patching, plugging, contraction, constriction, and scission
2. Removal of harmful materials
3. Replacement of damaged cellular components
4. Remodeling or adaptive responses

The Role of the Plasma Membrane in Disease Pathogenesis

Defective plasma membrane repair pathway and the inability to restore plasma membrane integrity can cause or exacerbate the pathogenesis of a variety of diseases such as inflammatory bowel disease, neurodegenerative disorders, and muscular dystrophies (MDs). Muscular dystrophies, for example, are often characterized by increased membrane permeability, resulting in degradation of the muscle and loss of function. Similarly, plasma membrane integrity is lost during Alzheimer’s disease and Parkinson’s disease pathogenesis, as the disease-associated proteins form aggregates.

Back to the Top