BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: amino acids

This Parasite Can Change Agriculture for the Better

When parasites take control of a host, it may seem like all is lost for the unfortunate animal. However, a newly discovered parasite uses a mechanism that actually slows down plant aging, and may offer new ways to protect crops that were once threatened by diseases. 

Prior to this discovery, very little was known on how this parasite functioned on both a molecular and mechanistic basis. The Hogenhout group at the John Innes Centre and collaborators published in Cell have identified a manipulation molecule produced by Phytoplasma bacteria, which hijacks the development of plants. This protein breaks down key growth regulators, which as a result causes abnormal growth.

According to an article published by FronteirsIn, phytoplasmas and their associated diseases cause severe yield loss globally. For example, Aster Yellows cause major yield losses in crops such as lettuce, carrots, and cereals. As stated in the article, “Phytoplasma diseases of vegetable crops are characterized by symptoms such as little leaves, phydolly, flower virescence, big buds, and witches’ brooms.” These effects ultimately cause the host plants to die over time. 

Phytoplasma Growing on a Plant

Professor Saskia Hogenhuot said that “Our findings cast new light on a molecular mechanism behind this extended phenotype in a way that could help solve a major problem for food production.” One of these findings includes the bacteria protein entitled SAP05, which manipulates the plant’s molecular structure. This manipulation targets the process of the proteasome, which breaks down obsolete proteins inside plant cells. SAP05 causes the plant proteins that are used for regulating growth and development to be thrown out. With the absence of the proteins, the plant’s development favors the bacteria, which in turn triggers vegetative growth and pauses the plant’s aging process.

Specifically, SAP05 directly binds to the plant developmental proteins and the proteasome. Proteasomes hold a very important role in the cell regarding the degradation of proteins, with Professor Gonzalez writing, “proteasomes perform crucial roles in many cellular pathways by degrading proteins to enforce quality control and regulate many cellular processes such as cell cycle progression, signal transduction, cell death, immune responses, metabolism, protein-quality control, and development.” Conversely, SAP05’s direct binding is a newly discovered method of degrading proteins, unlike the usual fashion of proteins degraded by proteasomes that are tagged with ubiquitin beforehand. 

To further study SAP05, the research team wanted to see if SAP05 affects the insects that carry the bacteria plant to plant. Turns out, SAP05 does not affect the insects due to the structure of the host proteins in animals differing enough from plants. This research also enabled the team to identify the two amino acids in the proteasome that interact with SAP05. If these two amino acids in the plant proteins were switched to the amino acids found in the insect protein, they would prevent abnormal growth. 

In a polypeptide chain, every amino acid is important to how the chain functions. Specifically, an amino acid’s unique side-chain gives it different characteristics, which plays a role in how the protein is structured and its function in the cell. In this case, these two amino acids from plant to insect proteins ultimately change the way SAP05 interacts with the polypeptide chain, which as a result changes the effect. 

Personally, I feel that this discovery is groundbreaking since it enables countless possibilities regarding the prevention of mass yield loss. How do you think this research will be utilized in the future? Let me know in the comments!

Gerbils Can You Hear Me?

80 to 90 percent of people suffer from inherited deafness. In a study, scientists have reversed deafness in gerbils. This is a huge step in gene therapy research this month making the possibility of using gene therapy as a cure for deftness one step closer. Genetic therapy is the use of genetic material such as DNA to manipulate a cell and is generally used to treat inherited diseases; in this case scientists used human embryonic stem cells. The gerbils in the study were born deaf. This type of deafness is a birth defect caused by damage to hair cells in the inner ear. These inner ear hair along with auditory neurons which translate sound vibrations from the inner-ear cells to electrical signals are how you can hear. Scientists specifically worked on gerbils whose deafness was caused by a mutation in a gene coding for a protein called vesicular glumamate transporter-3. Even minor alterations to a protein’s primary structure ,such as the movement of a double bond, will cause major defects in the tertiary structure and the function of the protein. The mutated protein in this study vesicular glutamate transporter-3 controls the consumption of glutamate (neurotransmitter) into synaptic vesicles, which join two nerve cells, of the neural cells. This is clearly groundbreaking news this month and has proved the various use of stem cells. How do you feel about the use of embryonic stem cell research? Feel free to comment!!

 

 

Amino Acids and Autism

Photo Credit to fotopedia.com

According to a recent study, an amino acid deficiency may be to blame for a rare form of hereditary autism. As stated in the Nature magazine article, genome sequencing in six children with Middle Eastern backgrounds uncovered “mutations in a gene that stops several essential amino acids being depleted” (Callaway). These mutations inactivate the enzyme BCKD-kinase. As we discussed in class, an enzyme increases the rate of a chemical reaction. However, why the lack of this enzyme would cause autism is still unknown.

Joseph Gleeson, a child neurologist who headed the study, suggests that low levels of branched amino acids to the brain, high levels of larger amino acids , or both might be behind autism symptoms.

Mice who also lacked BCKD-kinase exhibited tremors and epileptic seizures common to autism. However, when given dietary supplements of the branched amino acids, the chemical imbalance was treated and their symptoms disappeared.

Supplements given to the autistic children normalized their blood levels of amino acids. The patients’ conditions did not worsen, however, there was no real evidence that symptoms were reduced. Consequently, Gleeson hopes to conduct a clinical trial testing the effectiveness of dietary supplements in mitigating symptoms of autism and further identify children with the gene mutations for BCKD-kinase.

Matthew Anderson states that Gleeson’s study will “encourage other researchers to explore metabolic pathways as causes of autism.”

The amino acid deficiency may only compose a small percentage of all autism cases, but this is still a large step. The results of further study may present us with the “first treatable form of autism” (Gleeson).

Comments welcome!

 

Gamers solve some of biology’s most difficult riddles?

Who is solving some of biology’s most difficult puzzles and riddles? Obviously scientists, right? Think again. It’s the gamers.

An article recently reported that a revolutionary online game called Foldit, allows anyone, from gamers to students, to help predict the foldings and structures of  various proteins by playing competitively online. Protein folding is one of biology’s most difficult and costly problems, and is even a troublesome task for the most capable computers. A game such as Foldit requires much insight and an intuitive understanding to fold the proteins, allowing human intuition to triumph over a computer’s calculations. As we have learned in class, proteins are very prevalent in the human body. Hormones, enzymes, and antibodies are all examples of proteins, but many proteins are also associated with strands of viruses and diseases.

This is where you, as the gamers, come into the picture.

Since proteins play a large role in the functions of viruses and diseases, gamers playing Foldit can help design new proteins to help treat or provide a cure for the condition. The article reported that gamers have most recently solved the structure of an enzyme crucial for the reproduction of the AIDS virus. Knowing the structure, scientists are now able to find certain drugs to neutralize the enzyme and stop the reproduction of AIDS virus.

In class, we have learned that there is basically an infinite amount of combinations of proteins; there are 20 amino acids and can be combined to form chains of various lengths. We have also learned that the structure of a protein is also correlated with its function. The bonds present in the primary, secondary, tertiary, and quaternary structures of proteins are an important part to the shape and folds of a protein, giving the protein certain properties due to its shape. All of the information we have learned about proteins in our AP Biology class, can be seen and easily applied to the game, Foldit.

Now since we know the vital importance of proteins, do you want contribute to the next cure for a virus or disease? Get your game on and try Foldit out and see what you can do to solve some of biology’s most difficult riddles!

 

 

 

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