The Roles Of DNA : The Development Of Complex Proteomes

We will not go through the process here, but as an illustration of this “alternate splicing”, remove codons (beads) 52 - 66 from your sentence above.

Deletion – this is the removal of a gene portion on a DNA strand. Consequently the sequencing of the amino acid on the polypeptide chain is altered, resulting to production of a wrong protein, also have Frameshift impact on the protein.

Nonsense mutation is from AAG to AAA, the amino acid will still be a lysine at that position, but it changes the recognition sequence for splicing. The intron won’t be removed.

It took an additional six years for researchers to glimpse at the functions provided by SMN1. Meister et al. categorized the SMN1 protein an essential to promote correct assembly of U12 small ribonucleoproteins (snRNPs). In genetics, snRNPs are nucleic proteins responsible for the splicing of premature ribonucleic acid chains (pre-mRNA) derived from genes. Without correct splicing, mature ribonucleic acid chains (mRNAs) produce dysfunctional proteins when translated. In this case, splicing functionality of U12 - intron containing transcripts is lost, and because the transcript is wrongly coded, its translation will produce a functionless protein. Hence, loss of SMN1 results in an inability form U12 snRNPs splicing complexes, and reduced splicing functionality results in loss of U12 - intron splicing functionality (Patel and Steitz, 2003).

Once upon a time in a far off nucleus, lived a king named DNA. DNA had no family, no friends, and was extremely lonely. Well one day, a wicked witch named DNA/RNA polymerase came and demanded the DNA’s attention. He took extra care of her and asked if he could have a wish. She says that she knows what he wants and warns him to be careful of what he wishes for. She told him that he would not have to be lonely, but at of pain. He agrees and the witch casts the spell of transcription on him. DNA is copied from the spell creating a beautiful princess mRNA.

Before leaving the nucleus the pre-mRNA may go through a process called RNA splicing (Brooker). During this process the undesirable introns are disposed of while the coding sequences, exons, are spliced together to form messenger RNA (Brooker). Understanding RNA splicing, the most important process that may alter a protein’s shape is alternative splicing (Brooker). This process allows one strand of pre-messenger RNA to produce several different polypeptide sequences (Brooker). One pre-mRNA can create multiple polypeptide sequences which in turn creates proteins that are distinctive from each other. Alternative splicing is seen in the LMNA gene, it produces Lamins A and C (Swahari). Although they are different proteins, they are believed to be functionally redundant (Swahari). During the formation of these proteins a farnesyl group, which embeds into the cell membrane, is added to one end and later the protein is cleaved at a recognition site in exon 11 removing the tip and the farnesyl group (Swahari). Due to the point mutation linked to HGPS 50 amino acids are removed, within these is the recognition site (Swahari). As a result the protein is permanently farnesylated and known as progerin (Swahari). This protein imbeds and accumulates in the cell membrane creating the symptoms of HGPS (Swahari).

Furthermore, research has also revealed that circadian function within the SCN is also directly affected by HD. In another study using R6/2 mice, it was found that the mice’ night-day ratios were abnormal, revealing circadian disruption (Morton et al., 2005). In addition to their activity patterns, the mice’ SCN activity were also directly measured using electrodes and a clamp. After monitoring, it was found that the expression of their clock genes was severely disrupted. While knowing that circadian rhythms directly within the SCN are altered in organisms with HD is an essential step to find the most efficient treatment to normalize these organisms, it does not reveal the way in which Huntington’s

She describes interval timing and the circadian clock as the main neural timekeepers. Wright states that interval timing is a form of timekeeping concentrated in the brain and the firing of neurons and its cycles to form specific “time stamps” for certain events and is used to measure short periods of time. Whereas the circadian clock regulates body process to occur within 24 hour cycles. Then she expands on seasonal changes and the effects caused to the daily rhythms of the body. Biological clocks are intertwined with human health ranging from Parkinson’s disease to seasonal

Changes in aged circadian clock are already described in many levels (for review see Engelberth et al., 2013), such as decreases in rhythm amplitude and phase duration controlled by the clock (Satinoff et al., 1993), fragmentation of locomotor activity rhythm (Valentinuzzi et al., 1997), reduction in expression of immediate early genes c-fos and NGFI-A after photic stimulation (Sultin et al., 1993), loss in rhythm expression of Bmal transcript and in Controlled-clock genes, Dbp and Dec1, involved in molecular machinery regulation of biological clock (Bonaconsa et al., 2014),decreases in electrical intercellular synchronization and membrane conductance during night time (Nakamura et al., 2011; Farajnia et al., 2012). Regarding morphological and neurochemichal findings, aged SCN have a reduced immunoreactivity of vasoactive intestinal polypeptide (Krajnak et al., 1998) and vasopressin (Cayetanot et al., 2005) in addition to a loss in neuron number in rats (Tsukahara et al., 2005) and marmosets (Engelberth et al., 2014). Current data, however, are focused only in SCN, which brings limitations to understanding the whole process of how aging influences the CTS, since this system has other integrated components which may also be affected (Yamanazaki et al., 2002; Davidson et al., 2008). For instance, the only existing data about the aging effects in

Maurice Wilkins deserves the most credit for the discovery of DNA’s structure because without his research, it could’ve been years before DNA’s structure was truly understood. This is due to the fact that Wilkins was the first person to ever produce a photograph of DNA. He did this by using X-Ray Crystallography. Now, many will say that Rosalind Franklin provided a clearer, better picture, known a Photograph 51, than Wilkins ever did which ultimately lead to the discovery of DNA’s structure. However, she worked off Wilkins idea of using X-Ray Crystallography and would therefore never have produced the picture of DNA without his work. Others will say that Watson and Crick are the rightful heirs to the title of discovering DNA’s structure. However,

When the human genome sequence was released in 2003, it was discovered that it contains only 23,000 genes (Crollius et al., 2000 as cited in Chen, 2012). In comparison, the nematode C. elegans, a much simpler organism, has a similarly sized genome. This demonstrates that there is no real connection between gene number and organismal complexity. The concept of one gene leading to the formation of only one protein is no longer valid. Instead, a posttranscriptional process called alternative splicing (AS) exists in which various unique transcripts, or isoforms, can be produced from a single gene in eukaryote organisms. It involves removing introns from a strand of pre-mRNA, while splicing the remaining exons together to produce the mature

 Jet Lag: internal biological clocks collide with external clocks as a result of moving across several time zones.

Transposable elements (TEs) such as Arthrobacter luteus (Alu) sequences make up approximately 20% of the human DNA genome. The repeated DNA sequences were once thought to be “junk” for decades after its discovery in the 1940s, however, recent data suggest that these sequences cause codon alteration and splice site relocation. Ultimately these events change the human genome. The transposable elements are believed to have risen from retrotransposition and constant RNA editing over evolution (Kim 2013). The primary mechanism for retrotransposition is caused by adenosine deaminases acting on RNA (ADARs). ADAR reactivity and potency will enable scientists to track small RNA and gene interference activities. The retrotransposition of RNA into common introns serve as indicators of sites of cancer initiation, progression, and therapeutic effects. The influx in the concentration and frequency of production Alu sequences trigger sequence mutation, generating different protein isomers, leading to cancer (Crews 2015).

Deletion Mutation: is a type of gene mutation wherein the deletion of nucleotides causes a shift in the reading frame of the

The biological clock is an organism’s rhythm that controls the cycle of behaviors that occur on a daily basis. Slowing the biological clock is in reference to the cells that are constantly changing in an individual’s body. A person should take care of his or her body at a young age because the effects of the care will have outcomes as the person ages. There are several contributing factors to speeding up the aging process such as, stress, vitamin and mineral deficiency, or excessive food intakes. Reducing and or limiting these factors can play a major role in how the body continues to age. As an individual age his