Cell Membrane Resources
The plasma membrane of the cell is a dynamic structure that separates the intra and extracellular spaces and plays key roles in facilitating intercellular communication. Cell membranes are involved in many complex processes such as cell adhesion, receptor endocytosis, ion conduction, and exosome release. Therefore, understanding the composition of cellular membranes and their interactions is important in understanding many cellular functions.
Featured Products
Membrane Lipid Strips are used in simple protein-lipid overlay assays to help determine the specificity of your protein towards one or more of 15 different biologically important lipids.
Monoclonal antibody to PI(3,4,5)P3 for use with immunostaining and other in vitro applications.
Phosphatidic Acid Beads are composed of agarose with bound phosphatidic acid (PA) and are designed for use in protein pull-down experiments.
PI(4,5)P2 PolyPIPosomes are polymerized, liposome-like nanoparticles containing 5% PI(4,5)P2 and can be used for more complex applications such as surface plasmon resonance (SPR).
Phosphatidylcholine (PC) is generally the most abundant lipid in cell membranes. POPC is a phospholipid with 16:0 and 18:1 acyl chains and is commonly used for synthetic liposomes.
Cellular Membranes
The outer plasma membrane is primarily a barrier separating the interior of a cell from the extracellular space. Crossing the membrane is usually dependent on specific transmembrane proteins, although the plasma membrane is semi-permeable and some molecules pass by simple diffusion. This serves as one of the ways that homeostasis is maintained.
Other internal cellular membranes such as those for the organelles (nucleus, mitochondira, lysosome, etc) have their own proteins and mechanisms for regulating passage and transport of specific cargo and molecules.
Cell membranes also contain a wide variety of peripheral membrane proteins that participate in various signaling cascades thus adding another means by which cellular homeostasis can be maintained.
Lipid Composition
The specific lipid composition of a membrane is also critical to understanding the global and local functions of the membrane. One key facet of lipid composition is the fluidity of the membrane. The fluidity of the membrane is important not only for adaptation of cellular shape but also for regulating movement of transmembrane proteins and protein complexes within the membrane.
Cholesterol (right, top) in particular is important as a bidirectional regulator of fluidity as it can have a stabilizing or stiffening effect depending on the temperature. Membrane fluidity and structure can also be affected by the acyl chain length and saturation of lipids. Phosphatidylcholine (right, middle) is one of the most abundant phospholipids in the plasma membrane and the predominant species of this lipid contain double bonds which ‘kink’ the acyl chain which influences lipid packing.
Other membrane lipids, such as diacylglycerol (right, bottom), not only have structural functions but serve as intermediates in lipid metabolism and lipid signaling.
Lipid-Protein Interatctions
As mentioned above, membrane-associated proteins perform specific and important cellular functions. There are also cytosolic proteins that can transiently interact with lipids in signaling complexes. The biological processes involving lipid-protein interactions include, but are not limited to: cellular trafficking, metabolism, pathogen recognition, and membrane transport.
Therefore the ability to identify and investigate these interactions is critical to understanding the full picture of cellular biology.
| Protein Name | Description | Interacting Lipids | Reference | Uniprot |
|---|---|---|---|---|
| CHM7 | Putative component of the ESCRT complex. | Phosphatidic Acid | Thaller et al. 2021 | F2QNL8 |
| WDR45/45B | Component of the autophagy machinery that sorts cytoplasmic materials for degradation. | PI(3)P | Ji et al. 2021 | Q5MNZ6 |
| Rgd3 | Modulates and maintains Rho3 polarity during growth in budding yeast. | PI(4,5)P2 | Gingras et al. 2020 | N/A |
| PKCζ (protein kinase C zeta) | Calcium- and diacylglycerol-independent serine/threonine-protein kinase that functions in the PI3K pathway. | Phosphatidic Acid, Phosphatidylserine | Velnati et al. 2020 | Q05513 |
| Gellin A & B | Central effectors of wound-induced protoplasmic gelation. | Phosphatidic Acid | Nguyen et al. 2020 | N/A |
| IFITM3 | Endosomal protein that blocks viral infection. | PI(3,4,5)P3 | Lee et al. 2020 | Q01628 |
| ERD7 | Induced due to dehydration stress in plants. | PI(4,5)P2, PIPs | Barajas-Lopez et al. 2020 | O48832 |
| PDZD8 | Contributes to endosome maturation and intracellular calcium dynamics. | PI(4)P, PS | Shirane et al. 2020 | B9EJ80 |
| PATELLIN2 | Carrier protein that may be involved in membrane-trafficking events associated with cell plate formation during cytokinesis. | PI(4)P, PI(4,5)P2 | Montad et al. 2020 | Q56ZI2 |
| EHBP1 | An adaptor protein that regulates vesicular trafficking by recruiting Rab8 family members and EHD1/2. | PI(3)P, PI(5)P | Rai et al. 2020 | Q8NDI1 |
| RCD-1 | Regulates programmed cell death spores in the fungus Neurospora crassa. | PS, CL | Daskalov et al. 2020 | Q7S6F2 |
| LDHA | Catalyzes conversion of pyruvate to lactate. | PA | Hoshino et al. 2020 | P06151 |
| EXO70B1 | Component of an exocyst subcomplex specifically involved in autophagy-related membrane traffic. | PI(3)P, PI(5)P | Pecenkova et al. 2020 | Q9FGH9 |
| SidC | Anchors to membrane PI(4)P potentially for vacoule formation or as an adaptor. | PI(4)P | Weber et al. 2006 | Q5ZSK6 |
| PLC-d1-PH | Mediates production of the second messenger molecules DAG and IP3 | PI(4,5)P2 | Sidhu et al. 2005 | P51178 |
| p40 PX | Component of NADPH-oxidase | PI(3)P | Stahelin et al. 2003 | O43739 |
| Grp1-PH | PH domain of Grp1, a Guanine-nucleotide releasing factor | PI(3,4,5)P3 | Saxena et al. 2002 | Q15080 |
| Spo20p | Meiosis-specific subunit of the t-SNARE complex. | PA | Kassas et al 2017 | C7GLA2 |
| TRAF2 | Regulates activation of NF-kappa-B and JNK | PI(3)P | Workman et al. 2020 | Q12933 |
| ZmGLR | Role in cortical microtubule reorientation and maize leaf morphogenesis. | PIPn | Wang et al. 2019 | E9NMH5 |
| WDFY2 | Plays a role in endosomal control of AKT2 signaling. | PI(3)P | Sneeggen et al. 2019 | Q96P53 |
| Vps13B | Tethering factor in vesicle traffic between early and recycling endosomes. | PI(3)P | Koike et al. 2019 | Q80TY5 |
| VIPP1 | "Plays crucial roles in the biogenesis and repair of thylakoid membrane protein complexes" | PI(4)P | Theis et al. 2019 | Q66YD0 |
| Vav1 | Couples tyrosine kinase signals with the activation of the Rho/Rac GTPases. | PI(5)P | Rodriguez-Fdez et al. 2019 | P27870 |
| RASP2 | Plays a key role in rhoptry exocytosis. | PI(4)P, PI(4,5)P2, PA | Suarez et al. 2019 | A0A384KK73 |
| SopF | Type III secretion system effector protein. | PI(4)P, PI(3,4)P2, PI(3,4,5)P3 | Lau et al. 2019 | A0A0F7DID8 |
| SNX3 | Phosphoinositide-binding protein required for multivesicular body formation. | PI(3)P | Klose et al. 2019 | O60493 |
| RGS12 | Regulates G protein-coupled receptor signaling cascades. | PI(5)P | Schroer et al. 2019 | O08774 |
| RavD | Trafficking of Legionella-containing vacuoles. | PI(3)P | Pike et al. 2019 | A0A509GV61 |
| Psd2 | Possesses antifungal activity sensitive to inorganic cations. | PI(3)P, PI(5)P, Phosphatidylserine, Cardiolipin | Amaral et al. 2019 | P81930 |
| PLK1 | Serine/threonine-protein kinase that performs several important functions throughout M phase of the cell cycle. | mono-PIPs, PA | Lin et al. 2019 | P53350 |
| PKCζ | Calcium- and diacylglycerol-independent serine/threonine-protein kinase. | Sphingosine 1-phosphate, sphingosine | Kajimoto et al. 2019 | Q05513 |
| MPEG1/Perforin-2 | Perforin-like protein that functions within the phagolysosome to damage engulfed microbes. | Phosphatidylserine, Cardiolipin, PI, PI(4)P, PI(4,5)P2 | Pang et al. 2019 | Q2M385 |
| Mfn2 | Mitochondrial membrane protein with a role connecting ER membranes to mitochondria. | Phosphatidic Acid, Phosphatidylserine | Hernandez-Alvarez et al. 2019 | O95140 |
| CelTOS | Malaria parasite protein required for cell traversal in hosts. | PI(4,5)P2, PI(3,4,5)P3 | Punde et al. 2019 | A0A2R4QLJ4 |
| cGAS | Sensor of cytosolic DNA. | PI(4,5)P2 | Barnett et al. 2019 | Q8N884 |
| CKM | Catalyzes the transfer of phosphate between ATP and various phosphogens. | Phosphatidic Acid | Hoshino et al. 2019 | P07310 |
| EXO70H4 | EXO70 subunit of the exocyst complex. | Phosphatidylserine, Cardiolipin | Kubatova et al. 2019 | Q9SF51 |
| GRAMD1A | Cholesterol transfer protein. | predominantly mono-PIPs | Laraia et al. 2019 | M0R0J9 |
| Irgb6 | Involved in innate cell-autonomous resistance to intracellular pathogens. | mono-PIPs, Phosphatidylserine | Lee et al. 2019 | Q62293 |
| K-Ras4B | Binds GDP/GTP and possess intrinsic GTPase activity. | Most PIPs, Phosphatidic Acid | Cao et al. 2019 | P01116 |
| GPA5 | Plant-unique phox-homology domain-containing protein. | PI(3)P | Ren et al. 2020 | N/A |