Allan Albig, Boise State University

Think back to that basic biology class you took in high school. You probably learned about organelles, those little “organs” inside cells that form compartments with individual functions. For example, mitochondria produce energy, lysosomes recycle waste and the nucleus stores DNA. Although each organelle has a different function, they are similar in that every one is wrapped up in a membrane.

Membrane-bound organelles were the textbook standard of how scientists thought cells were organized until they realized in the mid-2000s that some organelles don’t need to be wrapped in a membrane. Since then, researchers have discovered many additional membraneless organelles that have significantly changed how biologists think about the chemistry and origins of life.

I was introduced to membraneless organelles, formally called biomolecular condensates, a couple years ago when students in my lab observed some unusual blobs in a cell nucleus. Unbeknownst to me, we had actually been studying biomolecular condensates for years. What I finally saw in those blobs opened my eyes to a whole new world of cell biology.

Like a lava lamp

To get a sense of what a biomolecular condensate looks like, imagine a lava lamp as the blobs of wax inside fuse together, break apart and fuse again. Condensates form in much the same way, though they are not made of wax. Instead, a cluster of proteins and genetic material, specifically RNA molecules, in a cell condenses into gel-like droplets.

Some proteins and RNAs do this because they preferentially interact with each other instead of their surrounding environment, very much like how wax blobs in a lava lamp mix with each other but not the surrounding liquid. These condensates create a new microenvironment that attracts additional proteins and RNA molecules, thus forming a unique biochemical compartment within cells.

As of 2022, researchers have found about 30 kinds of these membraneless biomolecular condensates. In comparison, there are around a dozen known traditional membrane-bound organelles.

Although easy to identify once you know what you are looking for, it’s difficult to figure out what biomolecular condensates exactly do. Some have well-defined roles, such as forming reproductive cells, stress granules and protein-making ribosomes. However, many others don’t have clear functions.

Nonmembrane-bound organelles could have more numerous and diverse functions than their membrane-bound counterparts. Learning about these unknown functions is affecting scientists’ fundamental understanding of how cells work.

Protein structure and function

Biomolecular condensates are breaking some long-held beliefs about protein chemistry.

Ever since scientists first got a good look at the structure of the protein myoglobin in the 1950s, it was clear that its structure is important for its ability to shuttle oxygen in muscles. Since then, the mantra for biochemists has been that protein structure equals protein function. Basically, proteins have certain shapes that allow them to perform their jobs.

The proteins that form biomolecular condensates at least partially break this rule since they contain regions that are disordered, meaning they do not have defined shapes. When researchers discovered these so-called intrinsically disordered proteins, or IDPs, in the early 1980s, they were initially confounded by how these proteins could lack a strong structure but still perform specific functions.

Later, they found that IDPs tend to form condensates. As is so often the case in science, this finding solved one mystery about the roles these unstructured rogue proteins play in the cell only to open another deeper question about what biomolecular condensates really are.

Bacterial cells

Researchers have also detected biomolecular condensates in prokaryotic, or bacterial, cells, which traditionally were defined as not containing organelles. This finding could have profound effects on how scientists understand the biology of prokaryotic cells.

Only about 6% of bacterial proteins have disordered regions lacking structure, compared with 30% to 40% of eukaryotic, or nonbacterial, proteins. But scientists have found several biomolecular condensates in prokaryotic cells that are involved a variety of cellular functions, including making and breaking down RNAs.

The presence of biomolecular condensates in bacterial cells means that these microbes aren’t simple bags of proteins and nucleic acids but are actually more complex than previously recognized.

Origins of life

Biomolecular condensates are also changing how scientists think about the origins of life on Earth.

There is ample evidence that nucleotides, the building blocks of RNA and DNA, can very plausibly be made from common chemicals, like hydrogen cyanide and water, in the presence of common energy sources, like ultraviolet light or high temperatures, on universally common minerals, like silica and iron clay.

There is also evidence that individual nucleotides can spontaneously assemble into chains to make RNA. This is a crucial step in the RNA world hypothesis, which postulates that the first “lifeforms” on Earth were strands of RNAs.

A major question is how these RNA molecules might have evolved mechanisms to replicate themselves and organize into a protocell. Because all known life is enclosed in membranes, researchers studying the origin of life have mostly assumed that membranes would also need to encapsulate these RNAs. This would require synthesizing the lipids, or fats, that make up membranes. However, the materials needed to make lipids likely weren’t present on early Earth.

With the discovery that RNAs can spontaneously form biomolecular condensates, lipids wouldn’t be needed to form protocells. If RNAs were able to aggregate into biomolecular condensates on their own, it becomes even more plausible that living molecules arose from nonliving chemicals on Earth.

New treatments

For me and other scientists studying biomolecular condensates, it is exciting to dream of how these rule-breaking entities will change our perspective on how biology works. Condensates are already changing how we think about human diseases like Alzheimer’s, Huntington’s and Lou Gehrig’s.

To this end, researchers are developing several new approaches to manipulate condensates for medical purposes like new drugs that can promote or dissolve condensates. Whether this new approach to treating disease will bear fruit remains to be determined.

In the long term, I wouldn’t be surprised if each biomolecular condensate is eventually assigned a particular function. If this happens, you can bet that high school biology students will have even more to learn – or complain – about in their introductory biology classes.

Allan Albig, Associate Professor of Biological Sciences, Boise State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Jean-Luc Margot, University of California, Los Angeles

On Nov. 9, 2024, the world will mark Carl Sagan’s 90th birthday – but sadly without Sagan, who died in 1996 at the age of 62.

Most people remember him as the co-creator and host of the 1980 “Cosmos” television series, watched worldwide by hundreds of millions of people. Others read “Contact,” his best-selling science fiction novel, or “The Dragons of Eden,” his Pulitzer Prize-winning nonfiction book. Millions more saw him popularize astronomy on “The Tonight Show.”

What most people don’t know about Sagan, and what has been somewhat obscured by his fame, is the far-reaching impact of his science, which resonates to this day. Sagan was an unequaled science communicator, astute advocate and prolific writer. But he was also an outstanding scientist.

Sagan propelled science forward in at least three important ways. He produced notable results and insights described in over 600 scientific papers. He enabled new scientific disciplines to flourish. And he inspired multiple generations of scientists. As a planetary astronomer, I believe such a combination of talents and accomplishments is rare and may occur only once in my lifetime.

Scientific accomplishments

Very little was known in the 1960s about Venus. Sagan investigated how the greenhouse effect in its carbon dioxide atmosphere might explain the unbearably high temperature on Venus – approximately 870 degrees Fahrenheit (465 degrees Celsius). His research remains a cautionary tale about the dangers of fossil fuel emissions here on Earth.

Sagan proposed a compelling explanation for seasonal changes in the brightness of Mars, which had been incorrectly attributed to vegetation or volcanic activity. Wind-blown dust was responsible for the mysterious variations, he explained.

Sagan and his students studied how changes to the reflectivity of Earth’s surface and atmosphere affect our climate. They considered how the detonation of nuclear bombs could inject so much soot into the atmosphere that it would lead to a yearslong period of substantial cooling, a phenomenon known as nuclear winter.

With unusual breadth in astronomy, physics, chemistry and biology, Sagan pushed forward the nascent discipline of astrobiology – the study of life in the universe.
Together with the research scientist Bishun Khare at Cornell University, Sagan conducted pioneering laboratory experiments and showed that certain ingredients of prebiotic chemistry, called tholins, and certain building blocks of life, known as amino acids, form naturally in laboratory environments that mimic planetary settings.

He also modeled the delivery of prebiotic molecules to the early Earth by asteroids and comets, and he was deeply engaged in the biological experiments onboard the Mars Viking landers. Sagan also speculated about the possibility of balloon-shaped organisms floating in the atmospheres of Venus and Jupiter.

His passion for finding life elsewhere extended far beyond the solar system. He was a champion of the search for extraterrestrial intelligence, also known as SETI. He helped fund and participated in a systematic search for extraterrestrial radio beacons by scanning 70% of the sky with the physicist and electrical engineer Paul Horowitz.

He proposed and co-designed the plaques and the “Golden Records” now affixed to humanity’s most distant ambassadors, the Pioneer and Voyager spacecrafts. It is unlikely that extraterrestrials will ever find these artifacts, but Sagan wanted people to contemplate the possibility of communication with other civilizations.

Advocacy

Sagan’s scientific output repeatedly led him to become an eloquent advocate on issues of societal and scientific significance. He testified before Congress about the dangers of climate change. He was an antinuclear activist and spoke out against the Strategic Defense Initiative, also known as “Star Wars.” He urged collaborations and a joint space mission with the Soviet Union, in an attempt to improve U.S.-Soviet relations. He spoke directly with members of Congress about the search for extraterrestrial intelligence and organized a petition signed by dozens of prominent scientists urging support for the search.

But perhaps his most important gift to society was his promotion of truth-seeking and critical thinking. He encouraged people to muster the humility and discipline to confront their most cherished beliefs – and to rely on evidence to obtain a more accurate view of the world. His most cited book, “The Demon-Haunted World: Science as a Candle in the Dark,” is a precious resource for anyone trying to navigate this age of disinformation.

Impact

A scientist’s impact can sometimes be gauged by the number of times their scholarly work is cited by other scientists. According to Sagan’s Google Scholar page, his work continues to accumulate more than 1,000 citations per year.

Indeed, his current citation rate exceeds that of many members of the National Academy of Sciences, who are “elected by their peers for outstanding contributions to research,” according to the academy’s website, and is “one of the highest honors a scientist can receive.”

Sagan was nominated for election into the academy during the 1991-1992 cycle, but his nomination was challenged at the annual meeting; more than one-third of the members voted to keep him out, which doomed his admission. An observer at that meeting wrote to Sagan, “It is the worst of human frailties that keeps you out: jealousy.” This belief was affirmed by others in attendance. In my opinion, the academy’s failure to admit Sagan remains an enduring stain on the organization.

No amount of jealousy can diminish Sagan’s profound and wide-ranging legacy. In addition to his scientific accomplishments, Sagan has inspired generations of scientists and brought an appreciation of science to countless nonscientists. He has demonstrated what is possible in the realms of science, communication and advocacy. Those accomplishments required truth-seeking, hard work and self-improvement. On the 90th anniversary of Sagan’s birth, a renewed commitment to these values would honor his memory.

Jean-Luc Margot, Professor of Earth, Planetary, and Space Sciences, University of California, Los Angeles

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Farha Abassi, Michigan State University

My three daughters and I arrived in Michigan from Pakistan in 2000.

Moving here was my choice, and I followed the legal process. Before the move, I had often been to the United States. I was familiar with the culture and spoke fluent English, so I thought I was prepared.

Resuming my career as a physician in the U.S. was arduous, but I finally passed all the qualifying exams and completed a psychiatry residency at Michigan State University in 2006. After finishing my studies, I stayed on as faculty.

Of course, there is nothing new or particularly unique about my family‘s experience. Immigration, whether it is out of choice or forced by conflict, has always been part of the American experience. After all, the U.S. Constitution was signed by seven first-generation immigrants.

Experts will tell you that immigration makes our country stronger economically, culturally and in fields like science and medicine. Since I’m a doctor, I’m well aware that 26% of licensed U.S. physicians and surgeons are immigrants.

But it is also true that immigrants like me face stresses that harm our
psychical and mental health.

I teach cultural psychiatry to medical students and residents, specifically how to provide culturally appropriate care to Muslim patients. After more than 20 years in Michigan, I’m deeply rooted in the Muslim and immigrant community, and I’ve seen firsthand how anxious and uncertain my community is about the 2024 presidential election.

Panic attacks and depression

Republican presidential candidate Donald Trump has called immigrants “bloodthirsty criminals” and the “most violent people on Earth.” He claims that immigrants were “poisoning the blood of our country.” Research shows, and I’ve seen personally, how this kind of talk can cause anxiety and depression in immigrants both undocumented and legal.

Undocumented immigrants and their families, who live in precarious conditions and in fear of being deported, are especially vulnerable to Trump’s calls for mass deportations.

History has taught us that a politician’s hateful words can lead to violence.

In the first half of 2024, the Michigan Chapter of the Council on American-Islamic Relations documented 239 complaints of discrimination against Muslims, an 81% increase over the same period in 2023. In the report, CAIR-MI Executive Director Dawud Walid attributed the uptick to “policies of elected officials, rhetoric of candidates running for office, along with victim blaming by some political pundits.”

Adding to the situation are the deepening crises in the Gaza Strip and Lebanon, which are making Muslims in Michigan, especially those with relatives in the Middle East, reel with palpable grief.

This rise in Islamophobia and fear of an uncertain future is taking a toll. American Muslims are twice as likely to attempt suicide compared with people from other faiths.

Anxiety in the voting booth

Like 73% of all Americans, immigrants are anxious about the election.

With the politicization of baseless claims of undocumented immigrants voting, the fact is that naturalized citizens – who have every right to take part in the election – are a formidable voting bloc, making up 1 in 10 of the nation’s eligible voters and about 5% in Michigan.

What’s more, naturalized citizens tend to vote at higher rates than native-born citizens.

Still, for many Muslims in Michigan, it is hard to know how to vote this year. I don’t trust either of the major parties.

Michigan’s Muslims are feeling devalued and disenfranchised.

A key Arab American political action committee based in Michigan refused to endorse either candidate this cycle. Although the PAC typically backs Democrats, this year it said “neither candidate represents our hopes and dreams as Arab Americans.”

In late September, a national group of three dozen Muslim American scholars and imams signed an open letter calling on Muslims not to vote for Democratic nominee Kamala Harris.

“We want to be absolutely clear,” the letter reads, “don’t stay home and skip voting. This year, make a statement by voting third party for the presidential ticket.”

A group called Listen to Michigan gained attention during the primaries by attracting more than 100,000 people to vote “uncommitted” as a protest against President Joe Biden’s funding of the war in Gaza. The group has stopped short of endorsing Harris but urged voters “not to cast their ballot for anyone but her.”

Still, some of my neighbors have decided to back Green Party candidate Jill Stein.

I know my vote is my voice, and I fully intend to participate in the electoral process. But I can’t trust any of the candidates to create a safe haven for my family – a place where my daughters and I can thrive and live our American dream.

Farha Abassi, Assistant Professor of Psychiatry, Michigan State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.