How Cells Protect the Body

Some of our best defenders
operate quietly as microscopic
machines within our cells

Spliceosome: How Cells Avoid Errors When Manufacturing mRNA (Heidelberg University, 7 Feb 2025). Scientists continue to peer ever more closely into one of the largest and most complicated molecular machines in the cell: the spliceosome. This machine is responsible for assembling DNA transcripts into correctly-sequenced messenger RNAs (mRNA) before they exit the nucleus to be translated in ribosomes. Scientists at this university found a quality control mechanism that uses a ‘do or die’ strategy to ensure success:

When an error in the precursor mRNA is detected, the spliceosome is blocked, the recruited control factors interrupt the “normal” cycle, and a molecular short circuit causes the spliceosome to disassemble.

Researchers uncover key insights into how the body protects against neuron damage (Rockefeller University, 28 Jan 2025). Tiny cilia in the glia cells act like antennae to detect damage to neurons and fly into action.

Neurons may get all the glory, but they would be nothing without glial cells. While brain cells do the heavy lifting in the nervous system, it’s the glia that provide nutrients, clean up waste, and protect neurons from harm.

Now, scientists have discovered a new mechanism by which these crucial supporting players detect and respond to neuron damage. Published in Nature Communications, the study describes how two key proteins allow glial cells to actively monitor the hair-like cilia that extend out of nematode dendrites, so that the glial cells can respond to injuries and prevent damage.

From muscle to memory: new research uses clues from the body to understand signaling in the brain (HHMI, 7 Feb 2025). A video animation in this press release shows how scientists found a ladder-like “network of subcellular structures [that] is responsible for transmitting signals in neurons.”

“We are showing that a structure – a beautiful structure – operating at a level of subcellular organization is having a huge effect on the way the entire neuronal system is operating vis-à-vis calcium signaling,” Lippincott-Schwartz says. “This is a great example of how, in doing science, if you see a beautiful structure, it can take you into a whole new world.”

Keeping the steps of cell division in line (University of Konstaz, 28 Jan 2025). Researchers at this German university found that cell division is highly controlled: “various mechanisms ensure that all of the steps are completed in the correct order.” One way is by formation of a “pocket” in protein cyclin B:

Cell division is key for life. Every organism – from the smallest yeast to complex human beings – depends upon the constant reproduction of individual cells. In this process, various mechanisms ensure that all of the steps are completed in the correct order and that no errors are incorporated into new cells. This is important because such errors can, for example, cause tumours to form. A research team at the University of Konstanz led by biologist Thomas Mayer has now discovered that one of these control mechanisms is guided by a small binding-pocket that helps cyclins from the B type to dock onto substrates and thus significantly impacts the correct sequence of cell division events.

Every moment, millions of silent machines in our cells keep us running and protect us from harm.

Cryo-EM structure and regulation of human NAD kinase (Science Advances, 24 Jan 2025). Advances in cryo-electron microscopy continue to bring details of molecular machines into sharper focus. This paper tells about new cryo-EM images of an important enzymatic cofactor named NADPH that is involved in assembling nutrient molecules.

Reduced [proton-depleted] nicotinamide adenine dinucleotide phosphate (NADPH) serves as a vital reducing cofactor for anabolic biosynthetic pathways, including lipid, nucleotide, and amino acid synthesis. In addition, NADPH fuels antioxidant systems, protecting cells from the reactive oxygen species…. Cells maintain NADPH pools in different subcellular compartments, such as the cytosol and mitochondria. NADPH levels are regulated by NAD kinases (NADKs), specifically cytosolic NADK and mitochondrial NADK2, which catalyze the synthesis of NADP+, the limiting precursor for NADPH production, within their respective locations.

Diagrams show four parts of the enzyme with pivots that move like hinges in response to post-translational modifications (PTMs) like phosphorylation (the attachment of a phosphate group). “In addition, other PTMs, including acetylation and methylation within the N-terminal domain (table S1), likely modulate NADK’s conformational state and activity, providing a versatile regulatory mechanism responsive to the cellular state.”

From youth to old age, our cells work nonstop to protect us and keep our systems humming.

Centrioles generate two scaffolds with distinct biophysical properties to build mitotic centrosomes (Science Advances, 7 Feb 2025). Centrioles are curious barrel-shaped structures that form in perpendicular pairs at the spindle during cell division (mitosis). “Mitotic centrosomes assemble when centrioles recruit large amounts of pericentriolar material (PCM) around themselves.” Hundreds of proteins are involved in centrosome formation.

By performing experiments with fruit flies, these scientists found that “Spd-2 orchestrates the assembly of two scaffolds, with distinct biophysical properties, that cooperate to build mitotic centrosomes in flies.” Numerous other proteins and cofactors are involved in the process. This sounds like irreducible complexity, doesn’t it? In frogs, just one domain of this enzyme contains 1,000 amino acids! It’s obvious that without accurate cell division, life (and evolution) would stop. Humans have a counterpart called CEP192 that is even more complicated.

We must constantly be reminded that life depends on millions of parts working together. Cells are marvels of engineering, as complex as cities. Learning the details of how cells work is key to immunizing oneself against the myth of Darwinian evolution. The number of miracles one has to believe to think these things “evolved” by trial and error should relegate evolutionary theory into the trash heap of history as one of the biggest blunders in the history of thought. Darwin didn’t know any of these details. Now that we have learned about most of these marvels within the last half century, we must hold the wonders of the cell up to people “to open their eyes, in order to turn them from darkness to light, and from the power of Satan to God, that they may receive forgiveness of sins and an inheritance among those who are sanctified by faith in Me” (Acts 26:18). There’s no excuse now. There never was (Romans 1:20).

Natural and Special Revelation: The Word and the World proclaim our Creator’s wisdom.