All of us can agree that walking through the marketplace with its babbling crowd and peak time rush is a hard task to achieve. Going past so many people, objects, street dogs and whatnot is not a comfortable experience at all for sure. Especially if you live in such a densely populated country as India, you are surely relating to every word so far. However, if you think that’s the worst then you are wrong. If it is ever possible to use a shrink ray and land on the cell membrane you will surely have a way worse experience than I have just talked about!
You might now be wondering how life can be at the cell membrane of our very own cells that we are made up of. Well, without further ado, let’s take a curiosity-driven voyage through the mystical nanoworld which makes us what we all are.
Part 1 (the Inception)
Now that we have reduced ourselves to nanoscale dimensions, we are ready to trod our way around the unknown crowd that have never encountered in our macroworld. As we go along keep your imaginative and creative minds open, as we are about to experience what is unreal to our normal senses.
Cell Membrane
Ladies and gentlemen welcome to the Plasma Membrane. The temperature outside is 37°C. For your own safety, kindly keep your seat belts fastened till the lipidcraft comes to a complete halt & the Seat belt sign is switched off. Ensure that you carry all your curiosity. You can now use your cell phones only to read further as we have come beyond the normal world. Thank you for choosing us & we hope you will enjoy your time at the cell membrane. Have a pleasant stay!
Look around yourself. you will only see branched structures jiggling and wiggling. Some are very tall and go down inside the membrane, while some are attached to the surface. While the tall structures are membrane proteins, the ones clinging on to the lipid membrane below are glycosylphosphatidylinositol (GPI) anchored proteins. You might also find some structures waving like flags at the crest of some proteins. Well, you might have just spotted some carbohydrate chains covalently linked to either the proteins (glycoproteins) or lipids (glycolipids). Like our flags denote our identity, these sugar extensions have an immense role in helping other cells or molecules to identify this cell.
References:
- Guigas, G., & Weiss, M. (2016). Effects of protein crowding on membrane systems. Biochimica et Biophysica Acta (BBA) – Biomembranes, 1858(10), 2441–2450. doi:10.1016/j.bbamem.2015.12.021
- Löwe, M., Kalacheva, M., Boersma, A.J. and Kedrov, A. (2020), The more the merrier: effects of macromolecular crowding on the structure and dynamics of biological membranes. FEBS J., 287: 5039-5067. https://doi.org/10.1111/febs.15429
- Duncan, A.L., Reddy, T., Koldsø, H. et al. Protein crowding and lipid complexity influence the nanoscale dynamic organization of ion channels in cell membranes. Sci Rep 7, 16647 (2017). https://doi.org/10.1038/s41598-017-16865-6
- Sezgin, E., Levental, I., Mayor, S. et al. The mystery of membrane organization: composition, regulation and roles of lipid rafts. Nat Rev Mol Cell Biol 18, 361–374 (2017). https://doi.org/10.1038/nrm.2017.16
- Fu, G., Tu, L.C., Zilman, A., Musser, S.M. (2017). Investigating molecular crowding within nuclear pores using polarization-PALM. eLife 2017;6:e28716. DOI: 10.7554/eLife.28716