Excerpts from Recent Articles from 2010

2013 Back Issues

something a little different... - December 2013
I have been writing up articles for Protein Spotlight for the past 13 years, doing my best to inject both a human touch and a little bit of art into each one. Earlier this month, I received for the very first time, something with just this mixture from a scientist who had been inspired by one of my recent articles – On Sex, Drugs and Satisfaction – all about neuropeptide F, the lack of sex and Drosophila melanogaster who is prone to turn to the benefits of alcohol if the act of mating has been denied him... (PDF version - [an error occurred while processing this directive] bytes)
an unexpected turn of events - December 2013
Life depends on exchange. To this end, and on the cellular level, molecules are continuously secreted for the purposes of signalling, strengthening, transporting, protecting… Sometimes, the primary role of a molecule can bring about an unforeseen consequence which – if positive – is gladly preserved for the benefit of the species. This seems to be the case for a particular form of a polysaccharide known as hyaluronan: high molecular mass hyaluronan, or HMM-HA. The polymer is secreted in large quantities in a rather peculiar animal – the naked mole rat, or Heterocephalus glaber – and is thought to be responsible, at least in part, for the animal’s exceptionally long life span, because of the total absence of any form of cancer. Consequently, understanding how HMM-HA achieves this – and particularly the enzyme which synthesizes it, hyaluronan synthase 2 – could pave the way to therapies able to fight off the formation of malignant tumours. (PDF version - 348K bytes)
UniProt cross references
Hyaluronan synthase 2, Heterocephalus glaber (Naked mole rat) : G5AY81
Hyaluronan synthase 2, Mus musculus, (Mouse) : P70312
a gait on the wildside - November 2013
Never take a walk for granted. Putting one leg in front of the other is not a simple affair. To most of us, it seems so easy. Yet walking – and its faster version, running – demands intricate neuron development and networking that is gradually set in place during the course of embryogenesis and very early childhood. Walking can be learned, as long as you have the correct bases to begin with. Watch a toddler taking its first steps. They lose balance. Cave in. Fall. But, within a few weeks, a small human – although far slower than most vertebrates – manages to master the technique of standing up and moving forward by using its two legs very successfully. The art of walking, or locomotion, demands close coordination between left, right, forward and backwards, as well as the limbs’ muscles – without which walking would be a difficult enterprise*. In the case of four-legged vertebrates, coordination is even more complex. Recently, Swedish scientists discovered a protein – the Duplex and Mab-3 related Transcription Factor – which is directly involved in a horse’s gait, and gives an insight into how locomotion, as a whole, is managed and organised both on the cellular and molecular level. (PDF version - 50K bytes)
UniProt cross references
Doublesex- and mab-3-related transcription factor 3, Mus musculus (Mouse) : Q80WT2
Doublesex- and mab-3-related transcription factor 3, Homo sapiens, (Human) : Q9NQL9
Doublesex- and mab-3-related transcription factor 3, Equus callabus (Horse) : F6W2R2
about water - October 2013
There is no life without water. However, living beings go through life with given amounts of water inside them. Which is why there has to be a system that sustains this balance, and prevents too much water from flowing in, or indeed pouring out. Too large a volume of water in an organism, or too small a one, brings about serious deficiencies, which can lead to an organism’s death. So Nature devised a water barrier which it built around all its creations – a sort of seal that makes sure the volume of water we carry within us remains as stable as possible. When this barrier is deficient, though, individuals can suffer from skin disorders known as ichthyosis – or dry skin – to varying degrees: some mild, others lethal. Since the 1920s, it has been known that fatty acids have a role in mammalian skin hydration. Recently, researchers discovered how two lipooxygenases – epidermis-type lipoxygenase 3 and 12 – have a crucial role in the construction of the mammalian water barrier – and hence our aqueous well-being – thanks to their interactions with essential fatty acids. (PDF version - 237K bytes)
UniProt cross references
Arachidonate 12-lipoxygenase 12R-type, Rattus norvegicus (Rat) : Q2KMM4
Arachidonate 12-lipoxygenase 12R-type, Homo sapiens, (Human) : O75342
Hydroperoxide isomerase ALOXE3, Rattus norvegicus (Rat) : D3ZKX9
Hydroperoxide isomerase ALOXE3, Homo sapiens, (Human) : Q9BYJ1
the geometry of intelligence - August 2013
All vertebrates have a skull. In which is lodged – and protected – one of the most important and complex biological tissues that exists, i.e. the brain tissue. When you compare the brains of different animals, there is one thing that stands out immediately: the amount of folds. The brain of a marmoset or mouse, for instance, seems almost smooth when put beside a sheep’s, or a human’s. It all has to do with available space. Human brain tissue presents such a large surface that the only way Nature has found to fit it into a rather small receptacle is to fold it many times – very much like inserting a large blanket into a small drawer. This folding has given the human brain the particular architectural characteristics it has; an architecture which – when altered – can cause severe neurological harm. Recently, scientists discovered a protein which has a direct role in folding brain tissue during brain development: TMF-regulated nuclear protein 1, or Trnp1. (PDF version - 227K bytes)
UniProt cross references
TMF-regulated nuclear protein 1, Mus musculus, (Mouse) : Q80ZI1
TMF-regulated nuclear protein 1, Homo sapiens, (Human) : Q6NT89
the root of the problem - July 2013
There is not one living being on earth that doesn’t need to eat. And we all go about it in the most ingenious ways. Humans go hunting in supermarkets. Dogs wait for food to appear in their bowls. Mosquitoes suck blood. Plants seep in light. Frogs await the passing fly. There are, however, organisms that go one step further in their quest for food, and that is to use another living being to produce what they need to eat. This is the realm of parasitism, some forms of which are particularly inventive. In this respect, one nematode, known as the soybean cyst nematode worm – or Heterodera glycines – is capable of taking advantage of soybean roots and modifying parts of them to erect the ideal feeding place. They do this by injecting effector proteins into the plant, a few of which are able to mimic plant proteins involved in plant development. These particular nematode proteins are known as CLE-related proteins and represent a very subtle way of twisting a host’s welcome to their advantage. (PDF version - 221K bytes)
UniProt cross references
CLE-related protein 1, Heterodera glycines, (Soybean cyst nematode worm) : Q9BN21
CLE-related protein 2, Heterodera glycines, (Soybean cyst nematode worm) : Q86RQ1
the intricacy of a smell - July 2013
We all need a nose. Inside this part of an animal’s body lie millions of olfactory receptors awaiting smells that they will send on to the brain. In turn, our brain will say whether the smell is good, or bad – a simple way of informing an animal of what could be potentially harmful for it or, on the contrary, beneficial. The mechanism is pretty straightforward and has evolved over time to give the best chances of survival to living species. As for humans, their olfactory capacities are naturally far less fine-tuned than a dog’s or a wild animal’s, but they remain essential nevertheless. We are still very much aware of smells that spell ‘not good’ or ‘lovely’, and react accordingly. For years, researchers have wondered whether the actual perception of a smell has a genetic basis. Much has already been written on the subject, and the answer seems to be ‘yes’. Recently, scientists discovered that the perception of the characteristic smell of cut grass has a genetic basis, and is probably under the influence of an olfactory receptor dubbed ‘olfactory receptor 2J3’, or OR2J3. (PDF version - 242K bytes)
UniProt cross references
Olfactory receptor 2J3, Homo sapiens, (Human) : O76001
a case for discomfort - June 2013
There is no life without smells. In the wild, smells – and the capacity to sense them – are the basis for survival for plants and animals. They are used to attract, seduce, repel or protect, and are with us night and day; so much so that life would seem very bland without them. On the whole, for any given species, a pleasant perfume implies that all is well, while a bad one suggests that something is wrong. The smells the human body gives off are a combination of who we are, what we eat, and the general state of certain metabolic cycles. When part of a metabolic cycle is deficient, a change in our bodily odours can occur. This is the unfortunate case of what is known as the ‘fish odour syndrome’, or trimethylaminuria. People afflicted with trimethylaminuria release a smell of rotting fish. The symptoms were first clinically described in the 1970s and, in the 1990s, scientists discovered the cause: a malfunction of an enzyme known as flavin-containing monooxygenase 3. (PDF version - 552K bytes)
UniProt cross references
Dimethylaniline monooxygenase [N-oxide-forming] 3, Homo sapiens, (Human) : P31513
the taste of sweet - May 2013
Humans have always sought to make life sweeter. In prehistoric times, sugar cane was already being grown for its sweetening powers, and the sugar added to beverages and food. But why do humans like what is sweet so much? This may well have evolved from our distant ancestors, as far back as those who bore little resemblance to us. In the wild, animals have to depend on colour but also taste – and its very close sister, smell – to distinguish what is edible from what is likely to be toxic. On the whole, bitter is better left alone. As things evolved, a sweet taste became a feeling that was comforting one way or another. So, slowly but surely, sweetness was added to all sorts of foods and liquids. And, today, sugar is usually part of a Westerner’s diet – whether we are aware of it or not. As a result, towards the end of the 20th century, it had become clear that sugar – or an excess of it – was proving to be harmful to the human population, and it was necessary to find ways of making life sweeter without the nasty side effects. In the early 1980s, one such sweetener was rediscovered in a South American plant, Lippia dulcis. Known as Hernandulcin, researchers have recently managed to isolate a key enzyme in its synthesis, known as (+)-epi-alpha-bisabolol synthase. (PDF version - 51K bytes)
UniProt cross references
(+)-epi-alpha-bisabolol synthase, Lippia dulcis, (Aztec sweet herb) : J7LH11
the silence within - March 2013
There can be little worse than seeing – and feeling - your own child retreat into a world that doesn’t involve yours. Especially at a period of life when contact with a mother and a father is such a vital component of an infant’s development. And such a pleasurable one for the parents. Autism hits about one child in a thousand – although the contours of the affliction remain a little hazy. There are many forms. Some more serious than others. Some widespread while others are rare, or even unique. The common denominator is what could be described as a characteristic aloneness, where those suffering from autism are unable to interact socially and communicate in the way most of us do. Today, researchers believe that autism has a strong genetic component and that certain mutations are at the heart of autistic behaviour. One such mutation affects an enzyme known as BCKDK and may well be responsible for a rare hereditary form of autism that could be treated with a specific diet. (PDF version - 499K bytes)
UniProt cross references
BCKDK, Homo sapiens , (Human) : O14874
a wretched tale - January 2013
We all need guidance in life. And sperm cells are no exception to the rule. In plants, as in all living beings that depend on sex to multiply, a male gamete has to reach a female gamete in order to fuse with it. All sorts of mechanisms are used for this to occur. And plants are among the most imaginative organisms on the planet, simply because their mobility is so reduced. As such, they depend on forms of mobility that surround them: wind, bees, wild animals… And they have exploited this remarkably. At the molecular level, however, plants are far more mobile. An example is pollen tube elongation. In mouse-ear cress (Arabidopsis thaliana), for instance, once the pollen is ready to germinate, a bulge protrudes from its surface, elongates – and forms what is known as the pollen tube. Hordes of molecules are involved in pollen tube elongation. But you also need something which can actually guide the tube towards the ovule. And its name is protein HAPLESS 2, or HAP2. (PDF version - 193K bytes)
UniProt cross references
Protein HAPLESS 2, Arabidopsis thaliana , (Mouse-ear cress) : F4JP36


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