High-Resolution Lab Experiments Show How Cells “Eat” – Solves 40-Year-Old Problem in Cell Biology

Cells Biology Illustration

A new study shows how cell membranes curve to create the “mouths” that allow the cells to consume things that surround them.

“Just like our eating habits basically shape anything in our body, the way cells ‘eat’ matters for the health of the cells,” said Comert Kural, associate professor of physics at The Ohio State University and lead author of the study. “And scientists did not, until now, understand the mechanics of how that happened.”

The study, published recently in the journal Developmental Cell, found that the intercellular machinery of a cell assembles into a highly curved basket-like structure that eventually grows into a closed cage. Scientists had previously believed that structure began as a flat lattice.

Membrane curvature is important, Kural said: It controls the formation of the pockets that carry substances into and out of a cell.

The pockets capture substances around the cell, forming around the extracellular substances, before turning into vesicles – small sacs one-one millionth the size of a red blood cell. Vesicles carry important things for a cell’s health – proteins, for example – into the cell. But they can also be hijacked by pathogens that can infect cells.

But the question of how those pockets formed from membranes that were previously believed to be flat had stymied researchers for nearly 40 years.

“It was a controversy in cellular studies,” Kural said. “And we were able to use super-resolution fluorescence imaging to actually watch these pockets form within live cells, and so we could answer that question of how they are created.

“Simply put, in contrast to the previous studies, we made high-resolution movies of cells instead of taking snapshots,” Kural said. “Our experiments revealed that protein scaffolds start deforming the underlying membrane as soon as they are recruited to the sites of vesicle formation.”

That contrasts with previous hypotheses that the protein scaffolds of a cell had to go through an energy-intensive reorganization in order for the membrane to curve, Kural said.

The way cells consume and expel vesicles plays a key role for living organisms. The process helps clear bad cholesterol from blood; it also transmits neural signals. The process is known to break down in several diseases, including cancer and Alzheimer’s disease.

“Understanding the origin and dynamics of membrane-bound vesicles is important – they can be utilized for delivering drugs for medicinal purposes but, at the same time, hijacked by pathogens such as viruses to enter and infect cells,” Kural said. “Our results matter, not only for our understanding of the fundamentals of life, but also for developing better therapeutic strategies.”

Reference: “De novo endocytic clathrin coats develop curvature at early stages of their formation” by Nathan M. Willy, Joshua P. Ferguson, Ata Akatay, Scott Huber, Umidahan Djakbarova, Salih Silahli, Cemal Cakez, Farah Hasan, Henry C. Chang, Alex Travesset, Siyu Li, Roya Zandi, Dong Li, Eric Betzig, Emanuele Cocucci and Comert Kural, 12 November 2021, Developmental Cell.
DOI: 10.1016/j.devcel.2021.10.019

Emanuele Cocucci, an assistant professor in Ohio State’s College of Pharmacy, co-authored this study, along with researchers from UC Berkeley, UC Riverside, Iowa State University, Purdue University and the Chinese Academy of Sciences.

5 Comments on "High-Resolution Lab Experiments Show How Cells “Eat” – Solves 40-Year-Old Problem in Cell Biology"

  1. Babu G. Ranganathan | January 2, 2022 at 7:45 am | Reply

    Babu G. Ranganathan*
    (B.A. Bible/Biology)

    THE CELL could not have evolved. A partially evolved cell would quickly disintegrate under the effects of random forces of the environment, especially without the protection of a complete and fully functioning cell membrane. A partially evolved cell cannot wait millions of years for chance to make it complete and living! In fact, it couldn’t have even reached the partially evolved state.

    CATCH-22 FOR EVOLUTIONARY ORIGIN OF LIFE

    Just having the right materials, elements, and conditions do not mean that life can arise by chance.

    Miller, in his famous experiment in 1953 showed that individual amino acids (the building blocks of life) could come into existence by chance. But, it’s not enough just to have amino acids. The various amino acids that make-up life must link together in a precise sequence, just like the letters in a sentence, to form functioning protein molecules. If they’re not in the right sequence the protein molecules won’t work. It has never been shown that various amino acids can bind together into a sequence by chance to form protein molecules. Even the simplest cell is made up of many millions of various protein molecules.

    What many don’t realize is that although oxygen is necessary for life’s processes, the presence of oxygen would prevent life from coming into being. This is because oxygen is destructive unless there are mechanisms already in place to control, direct, and regulate it, such as what we find in already existing forms of life.

    RNA and DNA are made up of molecules (nucleic acids) that must also exist in the right sequence. Furthermore, none of these sequential molecules, proteins, DNA, RNA, can function outside of a complete and living cell and all are mutually dependent on one another. One cannot come into existence without the other.

    Mathematicians have said any event in the universe with odds of 10 to 50th power or greater is impossible! The probability of just a single average size protein molecule arising by chance is 10 to the 65th power. The late great British scientist Sir Frederick Hoyle calculated that the odds of even the simplest cell coming into existence by chance is 10 to the 40,000th power! How large is this? Consider that the total number of atoms in our universe is 10 to the 82nd power.

    The cell could not have evolved. A partially evolved cell would quickly disintegrate under the effects of random forces of the environment, especially without the protection of a complete and fully functioning cell membrane. A partially evolved cell cannot wait millions of years for chance to make it complete and living! In fact, it couldn’t have even reached the partially evolved state.

    Alien beings, even if they do exist, could not have evolved. How could they have survived millions of years while the very biological structures, organs, and systems necessary for their survival were supposedly still evolving? Life, in any form (even a single-celled organism), must be complete, fully integrated, and fully-functioning from the very start to be fit for survival.

    Of course, once there is a complete and living cell then the code and mechanisms exist to direct the formation of more cells. The problem for evolutionists is how did the cell originate when there were no directing code and mechanisms in nature. Natural laws may explain how a cell or airplane works but mere undirected natural laws could not have brought about the existence of either.

    What about synthetic life? Scientists didn’t create life itself. What they’ve done is, by using intelligent design and sophisticated technology, scientists built DNA code from scratch and then they implanted that man-made DNA into an already existing living cell and alter that cell. That’s what synthetic life is.

    Through genetic engineering scientists have been able to produce new forms of life by altering already existing forms of life, but they have never created life from non-living matter. Even if they do, it won’t be by chance but by intelligent design. That doesn’t help the theory of evolution.

    What about natural selection? Natural selection doesn’t create or produce anything. It can only “select” from biological variations that are possible and which have survival value. If a variation occurs that helps a species survive, that survival is called ” natural selection.” It’s a passive process. There’s no conscious selection by nature, and natural selection only operates in nature once there is life and reproduction and not before, so it would not be of assistance to the origin of life.

    Science can’t prove we’re here by chance or design. Neither was observed. Both are positions of faith. The issue is which faith is best supported by science. Let the scientific arguments of both sides be presented.

    Read my popular Internet articles:

    THE NATURAL LIMITS TO EVOLUTION
    ANY LIFE ON MARS CAME FROM EARTH

    Visit my Internet site: THE SCIENCE SUPPORTING CREATION

    Author of the popular Internet article, TRADITIONAL DOCTRINE OF HELL EVOLVED FROM GREEK ROOTS

    *I have given successful lectures (with question and answer period afterwards) defending creation before evolutionist science faculty and students at various colleges and universities. I’ve been privileged to be recognized in the 24th edition of Marquis “Who’s Who in The East” for my writings on religion and science.

    • Torbjörn Larsson | January 2, 2022 at 2:22 pm | Reply

      This is irrelevant for discussing the paper.

      It is also erroneous, since evolution is known to be the basic process in biology. The strawman you propose has nothing to do with evolution, which happens in large populations over long times through most often small changes. For instance, we know that cells have evolved from a universal ancestor since they share a core genetic machinery.

      Interestingly, while you write pseudoscientific comments relating to religious “intelligent design” – seen to be wrong as per above – we just discovered by evolutionary methods how the entities you proclaim are impossible are our self organized ancestors.

      “Our earliest, ‘half-alive’ ancestor needed little boost from heat Life on Earth assembled itself in warm, mildly alkaline conditions, study says

      How Earth changed from a lifeless ball of rock, water, and gases to a blue planet teeming with organisms is one of science’s greatest puzzles. Life had to assemble out of chemical building blocks about 4 billion years ago. Some scientists have invoked spectacular sources of energy for life’s spark, such as a comet impact or lightning strike into a pool of primordial ooze; more recently, others have suggested life’s beginning didn’t require a large infusion of energy. Now, researchers have reconstructed the chemical reactions that would have allowed life to assemble. They found that as life was evolving, it only needed water, hydrogen, carbon dioxide (CO2), a dash of salt, and a little geothermal heat to get started.

      In 2016, evolutionary biologist William Martin at Heinrich Heine University (HHU) and colleagues compared the genomes of two types of evolutionarily ancient single-celled organisms, bacteria and archaea. By looking at the genes bacteria and archaea share, the researchers reconstructed the genome of the last universal common ancestor (LUCA) of all living things, they reported in Nature Microbiology. Having LUCA’s genome was a key step in understanding how nonliving chemicals organized themselves into living organisms.

      To further understand how LUCA came to exist, the researchers next explored LUCA’s metabolism—the set of chemical reactions it used to transform simple compounds into the building blocks of life. Martin and his colleagues compared the chemical reactions of bacteria and archaea, relying on the Kyoto Encyclopedia of Genes and Genomes, to find the reactions they had in common. Martin, lead author Jessica Wimmer, a graduate student in bioinformatics at HHU, and their colleagues uncovered 402 chemical reactions at the core of LUCA’s metabolism, they report this week in Frontiers in Microbiology. Many of the reactions only required hydrogen and CO2 to assemble more complex chemicals.

      Wimmer ran computer simulations of the 402 reactions, varying temperature and alkalinity. She and the team found that in an alkaline environment at 80°C to 100°C, more than 95% of the reactions would release energy. Because each reaction needs a heat boost to get started, one reaction can feed the next, keeping a protocell’s metabolism going. “The energy for life is in life itself,” Martin says. “It’s unfolding in these reactions.”

      Those findings narrow the number of places where life may have gotten its start, says Shino Suzuki, a microbiologist at the Japan Aerospace Exploration Agency who was not involved in the study. A nonvolcanic hydrothermal vent on the ocean floor seems like a good candidate. (Hydrothermal vents powered by molten rock would be too hot.) At those warm hydrothermal vents, certain iron-rich minerals react with water and produce the right amount of heat and alkalinity, and a steady stream of hydrogen gas for LUCA’s metabolism. Suzuki, Martin, and Wimmer think LUCA arose in these environments.

      In addition, such warm vents have rocks with microscopic pores that could have kept a set of metabolic reactions together in one place, before cell walls evolved. LUCA itself may have simply been a set of reactions happening within rock pores, only “half-alive,” Martin says. “It’s not a free-living cell,” he says. “It’s just a very advanced [combination of] chemical reactions.”

      Judit Šponer, a chemist at the Institute of Biophysics of the Czech Academy of Sciences is impressed with Martin’s reconstruction of LUCA’s metabolism and she agrees that a hydrothermal vent was probably where it all came together. But she doesn’t think the other components of life necessarily arose there. The necessary pieces for life—cell membranes, metabolic reactions, a genome—could have evolved in different places over millions of years, she says, and then somehow come together. “Life emerged in a variety of conditions,” she says.

      Martin’s work means life might also have arisen on other planets without dramatic heat or electric sources. “You need water, you need rocks, and a little bit of energy,” he says. “If you give life what it needs—namely hydrogen and CO2—that’s all you need.”

      [ https://www.science.org/content/article/our-earliest-half-alive-ancestor-needed-little-boost-heat ]

    • Torbjörn Larsson | January 2, 2022 at 2:27 pm | Reply

      To be clear, the title and subtitle of the Science article were two separate lines:

      “Our earliest, ‘half-alive’ ancestor needed little boost from heat
      Life on Earth assembled itself in warm, mildly alkaline conditions, study says”

      So we see that biology split from geology under evolution, from recurrent geological formations to replicating biological formations. And we also see that as expected the first cells were self organized half alive, assembled and at nurtured in their origin geological formation before they evolved biological self competence.

    • B.A. in Bible/Biology??? ROFLMAO

      “Author of a popular internet article”… This comedy just writes itself. Something that narcissists don’t realize is that people aren’t laughing with them – they are laughing at them.

  2. Torbjörn Larsson | January 2, 2022 at 1:57 pm | Reply

    I found an early preprint: https://www.biorxiv.org/content/10.1101/715219v2.full.pdf .

    It is a very elegant paper, with lots of work establishing the method and significance of result.

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