Page 42 - The Origin of Life and the Universe - International Conference 2016

6 it marks that protein with the ubiquitin molecule.
However, when generating the degradation signal,
Ubc6 enzyme first has to attach the ubiquitin molecule
to the faulty protein. Following this initial step, another
1 1 .
enzyme, Ubc7 steps in and forms a homogeneous
chain consisting of many ubiquitin molecules. Once
In a typical mammal cell, there are approximately the chain is completed, the annihilation process
ten to twenty thousand functioning protein varieties. begins. As it is seen, two separate enzymes are
For a cell to be healthy, these proteins need to be needed for the breakdown signal to be triggered. 2
healthy first. For this reason, the existence of intra- At this phase, proteasome, which consists of 33
cellular quality control mechanisms is crucial. subunits and two sub-complexes, detects the ubiquitin
The latest studies revealed a quality control system and breaks the marked protein's peptide bonds. The
made up from proteins: faulty protein has now been separated into its amino
A protein leaves the ribosome as a chain formed acids.
by thousands of amino acids, however it can't fulfill When we consider the fact that 30% of the proteins
its functions without transforming into the three-di- produced within the cell are defected, we can un-
mensional state folded onto itself. Proteins called derstand how vital a role this garbage disposal
chaperons transform these amino acid chains into system plays. Faulty production aside, in time, all
their designed final state and turn them into functional properly functioning proteins wear down and are
nano-machines. However, during this folding phase, replaced by new ones and that means proteins,
which requires sensitive connections at molecular which have reached the end of their lifespan, are li-
level, errors can be made and broken amino acid kewise marked and annihilated.
aggregates can be formed.
Accumulation of this waste material poses a health Each detail in our body is an indication of a
risk for the cell and the entire body. Alzheimer's and magnificent creation
Parkinson's diseases, various heart diseases, diabetes If it were not for this precise control system, we
and certain cancers arise due to improper handling could never speak of cellular health at all. This vital
of the intracellular protein balance. Faulty proteins balance system has to function with the same per-
cause "accumulation" by sticking to each other and fection inside each one of the almost 100 trillion cells
other proteins and therefore a cytotoxic effect, in that constitute human body, which can only be exp-
other words, intracellular intoxication ensues. 1 lained by a superior management and coordination.
For a cell to fulfill its functions in a healthy way, a Proteins overseeing other proteins, molecules
broad and effective quality control network has to be acting systematically in a specific order as well as
in process at any given time. For this, faulty proteins the degradation system being activated only when
should be collected and immediately removed from and where it is needed, can be explained neither
the cell. For this purpose, chaperon molecules and with coincidences nor other idle reasoning.
protein breakdown mechanisms that work in combi- It is obvious that the absence of even one step in
nation with each other have to be on continuous this process would lead to the cell’s death. There
duty. should be no deficiency in the entire system and all
While chaperons enable folding, they also play a should be working in coordination at the same time.
role in repair and maintenance tasks. They inspect This evidently guides us to the truth that there is only
other proteins for errors in quality. When they identify a single “Power” Who has knowledge of all things
a misfolded broken protein, they engage the protein- and created life and all living things. The Owner of
breakdown mechanism. This is the ubiquitin-pro- this marvelous and breathtaking Power is Almighty
teasome (protein degradation) system. God, Who knows and has dominion over all things in
Protein breakdown is an annihilation process kept the heavens and the earth.
under tight control through consecutive steps. In ad-
dition to chaperons, Doa10 ligase enzyme was dis- 1. In vivo aspects of protein folding and quality control, David Balchin, Manajit Hayer-
Hartl and F. Ulrich Hartl (June 30, 2016) Science 353 (6294), [doi:
covered to also detect faulty proteins. When 10.1126/science.aac4354]
2
2. Sequential Poly-ubiquitylation by Specialized Conjugating Enzymes Expands the
a Doa10 enzyme detects a faulty protein, Versatility of a Quality Control Ubiquitin Ligase. Annika Weber et al, Molecular Cell 63.
DOI: 10.1016/j.molcel.2016.07.020