Putting Down Roots

After much prodding by Raikhel, the airline provided her with a statement that the airplane had had to make an “unexpected landing.” “After that, I decided that I could not live in the Soviet Union anymore. This was the last drop,” says Raikhel, now director of the Institute for Integrative Genome Biology and a distinguished professor in the Center for Plant Cell Biology at the University of California, Riverside. She and her then husband, Alexander Raikhel, at the time a scientist at the Zoological Institute of the Academy of Sciences in Leningrad, asked to be fired from their positions—a way to protect their coworkers who could be punished by the regime for being associated with émigrés, as emigration was frowned upon in the Soviet state—and began to pack their bags. After only four months of waiting, they received permission to emigrate to Israel, says Raikhel.

“I never expected to be where I am today. When I was elected into the National Academy of Sciences I couldn’t believe
that this was happening to me.”

When Raikhel told her scientific supervisor she was leaving, he told her she was crazy. “‘You’ve made it here, you have a better life than most Russians, and you are dropping everything. You will be sweeping the streets of New York and your son will be selling newspapers,’ he told me. I told him, ‘Look, I could have been dead, and now I have a second chance at life.’” About 10 years later, Raikhel was reunited with the professor at an international cell biology meeting in Montreal, Canada.“I invited him to dinner, and he apologized for his statements.”

Because there were no direct flights to Israel from the U.S.S.R., everyone went through Vienna. Once there, Raikhel and her family decided to go to America and were sent by one of the American Jewish organizations to Rome for three months while waiting for permission to enter the U.S. “Less than a year after the plane crash, we were in Italy, in the free world, celebrating our son’s fourth birthday,” recalls Raikhel.

While in Vienna, Raikhel had written to University of Georgia protozoologist Jerome Paulin, who had visited her Leningrad lab, asking him for advice on how to look for a job, a process about which Raikhel, having always lived behind the Iron Curtain, had no clue. She received a telegram while in Rome that Paulin had found positions for both Raikhels: for Alexander, a postdoc in the department of entomology, and for Natasha, a temporary postdoctoral position in his own laboratory.

After working in the zoology department for a year, Natasha Raikhel seized an opportunity to join a cell biology lab in the botany department as a postdoctoral fellow. “The plant biology department was very active, with people like Joe Key who were instrumental in moving the plant research community forward and full of buzz about isolating genes and doing gene transformation in plants,” says Raikhel.

Raikhel’s initial studies on the distribution of wheat germ agglutinin in wheat seeds and adult plants led her to study the endomembrane system of plants, which sorts proteins and other cargo to various cellular compartments. Among the most cited of plant researchers, she pioneered the use of chemical genomics to perturb protein function in order to study essential proteins.

Here, Raikhel talks about how, after studying to be a concert pianist, she turned her sights to biology; how she discovered her talent as a mentor and motivator while starting the Center for Plant Cell Biology at UC Riverside; and how she works to empower women, especially in China, to become leaders in scientific research. 

Raikhel Reaches

A supportive childhood. Raikhel was born in Germany and moved back to Leningrad with her parents, a surgeon and an X-ray technician, when she was one and a half years old. “I had extremely good parents. They loved my sister and me dearly. I grew up very psychologically secure and happy in a loving home. I was quiet and very much into music.”

Unrealized aspirations. Raikhel began to study piano at age six, attending both a music school and a regular grade school. “I was sure that piano and music would be my life. I learned to be extremely disciplined, practicing for hours.” But in her final year of high school, Raikhel’s conducting teacher dashed her hope of becoming a concert pianist. “She asked me if I was sure I wanted to do this for the rest of my life and whether I had considered teaching piano. I looked at her incredulously, like ‘How could you even ask that?’ It didn’t take me long to figure out that I was not of the class of musicians destined to be professional performers.” Raikhel stopped attending the music school and took evening classes in physics and math to be competitive enough to get into university, hiring tutors with the money she earned as a music teacher. “I didn’t want to be a physician or engineer, but I loved nature, so I thought I would study biology. From my parents, I received unquestioning support. It was always ‘Natasha knows what she wants.’”

Steadfast focus. “I had to work unbelievably hard to catch up the first few years at the Leningrad State University. Most of my fellow students came from specialized biology, math, and chemistry high schools, and I came from music school,” says Raikhel. She was recruited by the invertebrate biology department to work on ciliated protozoa and earned a master’s degree. Raikhel met her husband at the university and both wanted to pursue PhDs. The school tried unsuccessfully to send the couple to conduct research in Vladivostok—close to the borders of China and North Korea. “We both knew that if we went there, we were finished,” says Raikhel. “Alex was finally given a job at the Institute of Zoology to make scientific labels for the insect department and, because I was his wife, I was given a job also—as a technician at a water purifying center, equivalent to the USDA. It was awful but we stayed in Leningrad.”

For two years, Raikhel worked there during the day and spent evenings and weekends doing research at the Institute of Cytology. Her husband maintained a similar schedule at the Institute of Zoology. “We were stubborn, and it finally became clear that no one was stopping us.” Raikhel’s advisor at the Institute of Cytology, Yuri Poljansky, saw how hard she was working and offered her a technician position in his laboratory. In February 1975, Raikhel defended her PhD and, as was customary at the time, was given a position as an assistant professor, working in the institute’s Protozoan Karyology Group. A few months later her first son was born.

Raikhel Rallies

Another move. After settling in Athens, Georgia, and switching to a plant biology laboratory at the University of Georgia, Raikhel worked with Michael Mishkind on plant lectins, abundant proteins in grains and legumes that bind carbohydrates and play an important role in plant immunity and response to stress. Together, they found that wheat germ lectin has different localization patterns in wheat, barley, and rye embryos. Raikhel continued to characterize the distribution and expression of lectins and, after seven years at the University of Georgia, applied for an assistant professor position in the Plant Research Laboratory (PRL) at Michigan State University. “I didn’t know at the time that it was the premier place in the country for plant biology.” Raikhel was invited to interview and fell in love with the place. “It was not because the institution was so renowned, which I didn’t even really know then, but because it was really international, and I felt at home there.” In 1986, Hans Kende, then the director of the PRL, offered her the position. By then her second son had just turned two. “We drove our car with the boys and our cat and a little trailer full of monoclonal antibodies in a nitrogen tank and all of our frozen materials. It wouldn’t be allowed now!”

Ahead of the curve. During her interview at the PRL, Raikhel had proposed to study cell type–specific expression of the sugar-binding protein known as wheat germ agglutinin and related lectins in monocots such as rice and barley and in some dicot plants. The project was almost impossible to pull off 20 years ago, and it is still very difficult even now in monocots like wheat, she says. “Monocots have complicated polyploid genomes, long life cycles, and are difficult to transform. The plants where this type of study was possible were the dicots, like Arabidopsis and tobacco plants, but the lectins we were studying were not found in Arabidopsis.”

Finding her niche. As Raikhel continued to work on wheat germ agglutinin in Michigan, she and her students noticed that the protein was synthesized as a precursor that was longer than the mature lectin. The protein was losing more than just the N-terminal signal peptide that directs it to be inserted to the endoplasmic reticulum. The lab found the C-terminus acts as a sorting signal to the vacuole, an organelle that can serve many functions, including trapping water and holding waste materials. This C-terminal portion is removed posttranslationally to form the mature protein.

The work led to the identification of sorting signals at the C-terminus of other proteins as well. When this signal was deleted, the protein was secreted instead of being targeted to the vacuole. Raikhel’s lab also added this signal to an unrelated protein that is normally secreted and was able to find it in the vacuole. “We did the study at the same time that yeast researchers found a different targeting signal for the yeast vacuole. I immediately concentrated my lab on understanding the mechanisms of trafficking to different organelles of the cell.”

Raikhel’s lab has since worked on the secretory system in plants and the mechanisms of protein synthesis, modification, and final delivery into the plasma membrane, cell wall, or vacuole. In the early 1990s, Raikhel’s lab began to work on Arabidopsis when the plant first started to become a popular plant model system. “I was trained as a cell biologist, so I had to learn genetics and molecular biology.”

A center of her own. In 2001, Raikhel was recruited to join the Department of Botany and Plant Sciences at UC Riverside, and to establish the Center for Plant Cell Biology. “I wanted the center to serve all science departments at the university. Infrastructure helps everyone. Science is complicated and there is no one that can do everything.” Raikhel hired a bioinformatician and a microscopy specialist and recruited new plant biology faculty. “I am good at pulling people together, and have learned that I have an innate ability to talk to and inspire people, but also to be straightforward. People come to me to discuss their strengths and weaknesses, and I know they trust me.”

A chemical bounty. In her new position, Raikhel began to focus on using chemical genomics to study the functions of essential plant proteins, as an alternative to using the classic genetics approach of mutagenesis to study gene and protein function. “Many genes that function in intermembrane trafficking are essential or redundant. Chemical biology allowed us to screen a library of chemicals and find ones that specifically perturb a protein of interest and study the phenotype.” In 2004, her lab’s first paper using the approach identified several compounds that could be used to study vacuolar sorting in Arabidopsis.

Chemicals as tools. Raikhel’s lab has continued to comb through chemical libraries in search of compounds useful in the study of plant molecular biology.  The team identified bioactive chemicals that block endocytosis—the process of protein delivery via vesicles—and also exocytosis, vesicular delivery to the outside of the cell. The chemicals could be useful to further elucidate these processes, says Raikhel. In another screen, Raikhel and her colleagues identified other bioactive chemicals that target endomembrane trafficking in Arabidopsis.

Raikhel Ruminates

An independent spirit. “I didn’t want to be that generation of immigrants that just came to this country because of their children. I wanted to live too, to have an independent life and not to put myself second always. But I never expected to be where I am today. When I was elected into the National Academy of Sciences I couldn’t believe that this was happening to me.”

Women’s ambassador. Raikhel often travels to China to give research talks, but also to speak to and mentor young female scientists. “They need to see more models of successful women in high positions, and there are not many there yet, unfortunately. I am helping to create a new institute and have convinced the institute to appoint a female scientist just elected to the Chinese National Academy of Sciences to be one of the codirectors.”

Music lover. “I go to concerts and the opera all the time, and I have a baby grand piano at home. I play just for myself, but maybe I will get a teacher and play more now that I am retiring.”

Art as life.  “Music and art have sustained me through emigration, divorce, cancer, and many problems that I have dealt with in life. It is such an important part of my life. Many scientists don’t have that same exposure. I had a rule in my lab in Michigan that no one could leave my lab until they visited the Art Institute of Chicago. One of my goals is to bring science and art together for young people, to organize a workshop and bring visual artists, musicians, and scientists together.” 

Greatest Hits

• Identified the sorting peptide signal that directs posttranslational processing of plant proteins and their transport to vacuoles
• Identified important genes that mediate vesicular trafficking machinery in plants
• Identified genes required for biosynthesis of xyloglucan, a major component of the cell wall in plants
• Was a founding director of the Center for Plant Cell Biology at the University of California, Riverside
• Was one of the pioneers of using chemical genomics to modify and study plant protein function
• As editor in chief of Plant Physiology from 2000 to 2005, revamped the journal into a high-impact plant biology publication