Problem solved: The chicken came first

What came first, the chicken or the egg?

People have struggled with this question for centuries, but now it seems that we have an answer.

Scientists conducted thorough research to investigate the proteins found in egg shells. It was found that the protein, called OC-17, is found in a chicken’s ovaries. This protein is essential for egg shell formation. The egg goes through many stages and one such stage is where the egg shell crystallizes and hardens in order to protect the egg yolk and fluid inside. At this stage the OC-17 comes into play. It is the mother’s ovaries that provide the egg with this essential protein. Thus, it is only possible for an egg to come from a chicken.

Remember, we are only talking about chicken eggs here.

Now that this age-old question has been answered, subsequent research will now focus on the reasons the chicken was crossing the road.

The malaria life cycle presents distinct opportunities for vaccine targeting

It is estimated that close to 1 billion people are infected with malaria each year, while two billion people remain at risk. There is currently no efficient vaccine, due in part to the parasite’s ability to confuse, hide, and misdirect the immune system.

As reported by the Malaria Vaccine Initiative, the malaria parasite develops both in humans and in the female Anopheles mosquito. In both hosts, the parasite moves through several life stages where it presents different antigens at each stage, highlighting distinct opportunities for vaccine targeting.

The above image provides a nice overview of this malarial life cycle, while indicating the three distinct stages that are the focus of vaccine development.

1. Malaria infection begins when an infected female Anopheles mosquito bites a person, injecting Plasmodium parasites, in the form of sporozoites, into the bloodstream.
2. The sporozoites pass quickly into the human liver.
3. The sporozoites multiply asexually in the liver cells over the next 7 to 10 days, causing no symptoms.
4. In an animal model, the parasites, in the form of merozoites, are released from the liver cells in vesicles, journey through the heart, and arrive in the lungs, where they settle within lung capillaries. The vesicles eventually disintegrate, freeing the merozoites to enter the blood phase of their development.
5. In the bloodstream, the merozoites invade red blood cells (erythrocytes) and multiply again until the cells burst. Then they invade more erythrocytes. This cycle is repeated, causing fever each time parasites break free and invade blood cells.
6. Some of the infected blood cells leave the cycle of asexual multiplication. Instead of replicating, the merozoites in these cells develop into sexual forms of the parasite, called gametocytes, that circulate in the bloodstream.
7. When a mosquito bites an infected human, it ingests the gametocytes, which develop further into mature sex cells called gametes.
8. The fertilized female gametes develop into actively moving ookinetes that burrow through the mosquito’s midgut wall and form oocysts on the exterior surface.
9. Inside the oocyst, thousands of active sporozoites develop. The oocyst eventually bursts, releasing sporozoites into the body cavity that travel to the mosquito’s salivary glands.
10. The cycle of human infection begins again when the mosquito bites another person.

Three dimensional structure of the VDAC membrane protein

Here, for your consideration, is the three dimensional structure of the VDAC membrane protein. As the name suggests it is found in the outer membrane of the mitochondria - the cellular energy source. Ain’t she pretty?

VDAC stands for “voltage-dependent anion channel” which means this protein functions as a pore, or channel, enabling the passage of small molecules from one side of the membrane to the other. The channel is able to adopt either an open or closed conformation depending on voltage differences between each side of the membrane.

VDACs are predominantly expressed in heart, liver and skeletal muscles, where concentrations of mitochondria are at their highest.

Fluorescent protein expression in a plant

This is a confocal micrograph of fluorescent proteins being expressed in the stem of Arabidopsis thaliana (thale cress seedling), a model plant often used in plant biology and genetics.

Drosophila Protein Interaction Map

This is a protein interaction map of Drosophila (fruit fly) that visualises the interaction and lines of communication between all proteins enabling each to accomplish their function. Determining the nature of these relationships is fundamental to the understanding of protein modes of action and cellular behaviour.

This map was developed as a starting point for studying dynamics of protein complexes in development and evolution.

Beautifully illustrated depiction of the central dogma of molecular biology

somersault1824:

A look into a eukaryote cell to see how proteins are made. DNA in the nucleus is ‘read’ by RNA polymerase, then ribosomes in the cytoplasm produce an amino acid strand that folds into a functional protein. Digitally painted for the National Science Foundation.

Nicole Rager Fuller

Co-discoverer of the structure of DNA, Francis Crick, coined the phrase ‘central dogma of molecular biology’ which states, in summary, that information in the form of DNA is converted to RNA which is translated into functional proteins.

The above image beautifully captures this mechanism where the DNA of the cell nucleus (yellow) is converted to single-stranded RNA (light blue), which is fed into a ribosome (dark blue). The ribosome translates RNA to a chain of amino acids that specifically fold to form a complete protein (purple).

Wild Poliovirus

This is a molecular graphics simulation of the Mahoney strain of wild poliovirus type 1, family Picornaviridae, genus Enterovirus. The capsid, or protein shell, is composed four structural units: VP1 (blue), VP2 (red), VP3 (yellow), and VP4 (green).  The RNA genome (purple) is shown within the capsid.

Viruses of the Picornaviridae family are often implicated in the onset of acute gastroenteritis, a common illness throughout the life of humans and animals.

The protein Death Star

This is HtrA, or High Temperature Requirement A - a protein found in humans, plants, and bacteria and is critical for the smooth operation of its host cell. It is also a very convincing Death Star look-a-like.

In times of cellular stress (such as an increase in temperature), proteins will eventually struggle to carry out their normal function. If left untreated these damaged proteins will aggregate, often resulting in cellular death. But these cells are not going to give up so easily - they have a contingency plan.  This contingency plan is in the form of HtrA, a protein that is enlisted to return cellular order and control and ultimately ensure their continued survival.

HtrA does this by carrying out one of two functions: it either repairs damaged proteins enabling them to continue to perform their cellular role, or it destroys them completely. Its ability to perform these seemingly antagonistic roles of both ‘repairer’ and ‘destroyer’ is quite remarkable and is a capability that is rarely seen in a single protein. 

Also unique, is its ability to form cage-like structures like the one shown above. Amazingly these ‘super-structures’ are actually comprised of 24 individual HtrA proteins that, upon sensing cellular stress signals, immediately mobilise around damaged proteins and effectively hold them captive while performing their repair/destroy function.

Cells should therefore feel safe in the knowledge that HtrA is there to protect them in times of stress - whether its by nursing damaged proteins back to health, or destroying them completely like its Star Wars equivalent would certainly do.