Astronomers have discovered 2026 ED138, a potential dwarf planet in the outer reaches of the Solar System, far beyond Pluto.
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Mitochondria: the beating heart of the eukaryotic cell
The outer membrane of mitochondria contains pore‐forming beta‐barrel proteins, which facilitate the diffusion of molecules of up to about 3,000 Dalton across the outer membrane. Beta‐barrel proteins are also found in the outer membranes of bacteria and chloroplasts, revealing the common evolutionary origin. Owing to this bacterial descent, mitochondrial beta‐barrel proteins are integrated from the ‘inside’, that is, from the intermembrane space (IMS). After being translocated through the TOM complex, precursors of beta‐barrel proteins are stitched into the outer membrane in an export‐like process by the sorting and assembly machinery (SAM) complex. Cryo‐electron microscopy structures of the SAM complex, in some cases with associated translocation intermediates, have recently revealed fascinating details of this machinery [5, 6, 7, 8]. Nils Wiedemann, Nikolaus Pfanner, and coworkers provide a comprehensive overview of the structure and function of the beta‐barrel assembly machinery [9].
During the evolution of eukaryotic cells, the IMS of mitochondria was derived from the periplasmic space of the endosymbiont. Presumably owing to the same evolutionary descent, soluble proteins of the bacterial periplasm and of the IMS reach their three‐dimensional structure by oxidative protein folding. The review by Christine Zarges and Jan Riemer describes the enzymes of the human IMS, which insert disulfide bonds into newly imported proteins [10]. The two major enzymes, the FAD‐bound sulfhydryl oxidase ALR/Erv1 and oxidoreductase CHCHD4/Mia40, are conserved from yeast to human. However, in humans, Mia40 is tethered to the inner membrane by the NADH dehydrogenase AIF adding an interesting regulatory component to the human mitochondrial disulfide relay.
Most mitochondrial proteins reside in the matrix. These proteins are synthesized in the cytosol with aminoterminal presequences to direct them into mitochondria. The presequence translocase of the inner membrane (also known as the TIM23 complex) facilitates their translocation across the inner membrane. Recent structures of the TIM23 complex of yeast showed that Tim17 represents the protein‐conducting essential subunit contradicting previous assumptions [11, 12]. Tim17 forms a half‐channel that is partially exposed to the lipids of the inner membrane and uses negatively charged residues to promote the passage of the positively charged presequences into the matrix [13]. In this ‘In the Limelight’ special issue of FEBS Open Bio, Agnieszka Chacinska and coworkers show models of the human TIM23 translocase and compare its structure to that of yeast cells [14].
Scientists Have Built a Robot Dog Powered by Human Brain Cells
Using living neurons as the foundation of computer chips promises to bring significant advantages over conventional systems in terms of both energy efficiency and adaptability: As sophisticated as AI is, the human brain needs a lot less power to run and is still much better at dealing with the unfamiliar.
The latest demonstration of this biological technology comes from scientists at Cortical Labs in Australia, who have fitted out a robotic dog with neurons grown in the lab that are able to direct it towards a target on a simple map.
By growing the neurons right on the chip, and fitting it with electrodes that provide two-way electrical signaling, the Cortical Labs team was able to translate activity in the small group of neurons into movement for the attached robot.
Anti-aging drug boosts brain blood flow in people at higher Alzheimer’s risk, study finds
A drug commonly used to prevent organ transplant rejection increased blood flow in the brains of healthy middle-aged adults who carry a genetic variant linked to a higher risk of Alzheimer’s disease, according to a new University of Missouri study.
Why you should care:
The findings could help researchers identify ways to delay or prevent Alzheimer’s disease in people who are genetically predisposed to developing the condition.
Copper drug restores memory and clears toxic Alzheimer’s proteins
Lead author Dr Jae Pyun (left), senior author Professor Joseph Nicolazzo (right).
Monash University researchers have found in laboratory experiments that a drug which delivers copper to the brain significantly reduces toxic Alzheimer’s proteins and improves long-term spatial memory.
The study, published today in the journal ACS Chemical Neuroscience, shows the compound Cu(ATSM) repairs a vital waste-clearing pump at the blood-brain barrier – unlocking a potential new avenue of therapeutics targeting neurovascular dysfunction, caused by one of the world’s leading causes of death.
Crazy Technology in 2000s Land Rover!
Jeremy shows a crazy technology from 2000s Land Rover, where driver and passenger can see different scenarios on the display.
Encryption Under Siege? OpenAI, Anthropic Disprove Key Cryptography Theorem
Cryptographers who develop encryption technologies may not be sleeping very well these days. OpenAI and Anthropic both said Monday that their internal AI models had disproven the Exponential Time Hypothesis, a longstanding computer science theorem that predicts the minimum difficulty of solving a…
Brain development eliminates flawed neurons to ensure genomic integrity
During fetal development, the human brain generates an excess of neurons, most of which are eliminated shortly before and after birth. New research from Harvard Medical School and Boston Children’s Hospital suggests that this is a critical quality-control mechanism.
A study published Oct 28 in Nature shows that neurons with multiple copy number variants — abnormal duplications or deletions of segments of DNA — are surprisingly widespread in the developing brain. Copy number variants can impact brain function and may contribute to neuropsychiatric conditions, including autism, schizophrenia, epilepsy, and intellectual disability.
But the research also shows that the vast majority of these flawed neurons are selectively eliminated, likely because the genomic alterations disrupt their ability to form synapses.
Elon Musk starts work on aggressive Bastrop County expansion
One of the new buildings is planned to have a 2.14 million-square-foot footprint.
High-speed microscopy reveals electrical activity across the brain
Within the brain, neurons compute by generating electrical impulses. These signals travel throughout neurons, which are in turn connected in vast networks that control brain functions such as sensory perception, memory formation, and control of movement.
In an advance that could help neuroscientists map those neural networks, leading to a better understanding of how neural activity underlies behavior and other brain functions, MIT engineers have invented a new microscope that can image electrical activity in neurons distributed across the brain of an entire organism, the experimental model Danio rerio (zebrafish).
Using a microscope that they adapted for fast, high-volumetric rate imaging, the researchers were able to track electrical activity across the brain on the scale of milliseconds. This method revealed patterns of neural activity from neurons throughout the brain that were activated in response to ultraviolet light.