Advanced Cell Biology II Step 1: How will you identify the “vital” cellular protein that the virus targets for degradation? (Hint: think proteomics). (3 pts.) First, since we know the viral RNA sequence and its targeting protein, we can investigate it in bioinformatics database, and can acquire some clues or hints about the target proteins. From the bioinformatics database, we might be able to find its structure, similarity with other proteins, functions, and binding domains. In other words, we can get some partial or complete amino sequences of the targeting proteins or information about likeness. Second, in order to further confirm the information about characteristics and function of the targeting protein that we have …show more content…
Since we have already known the amino sequence of the protein in previous step, we can narrow down the targeting ubiquitin ligase based on existing research data such as papers, NCBI data. There are many types of ubiquitin ligases in cells. However, we can make some candidate groups of targeting E3 based on the bioinformatics database. We will use antibodies which specifically bind to each type of ubiquitin ligase and impede its function. For example, the antibodies may covalently bind to the targeting ubiquitin ligase, and therefore, impede its function. Then, we will measure the amount of targeting protein. If we find that the amount of targeting protein is not changed in a cell, we can identify the target ubiquitin ligase. This is because only when the function of the target ubiquitin ligase is impeded, the degradation of the targeting protein will not be occurred. Step 3: What protein will be your drug target? What property of that protein will you target? Design an assay/approach to identify an antidote for “degron”. (4 pts.) Since "degron" targets a vital cellular protein for ubiquitin-dependent degradation, if we block its process of degradation, we can effectively turn off its effect. As mentioned earlier, ubiquitin ligase brings specificity. Since we have already known which ubiquitin ligase is
The virus fuses with the cell’s plasma membrane. The capsid proteins are removed, releasing the viral proteins and RNA. Reverse transcriptase catalyzes the synthesis of a DNA strand complementary to the viral RNA. Reverse transcriptase catalyzes the synthesis of a second DNA strand complementary to the first. The double-stranded DNA is incorporated as a provirus into the cell’s DNA. Proviral genes are transcribed into RNA molecules, which serve as genomes for the next viral generation and as mRNAs for translation into viral proteins. The viral proteins include capsid proteins and reverse transcriptase (made in the cytosol) and envelope glycoproteins (made in the ER). Vesicles transport the glycoproteins from the ER to the cell’s plasma membrane. Capsids are assembled around viral genomes and reverse transcriptase molecules. New viruses bud off from the host cell.
the specific Hemagglutinin genes, also known as the key to the cell. Once it has the correct
There is still a great deal of information to learn from the study of viruses and the continued exploration of the viral genome is crucial in understanding how viruses communicate, transmit from host to host and evade immune responses. The ever-change nature of the viral genome has shown us that the most dangerous viral infections of today may be undermined by newer and more effective viruses, resulting in catastrophic outcomes. Through the study of viruses, it is the hope of the scientific community to be ahead of the viral curve, preventing infections before they even
When a virus invades the human body there is an assortment of responses from the immune system relying largely on the particular pathogen type. Viruses invade the host with the purpose of replication to ensure survival. My cytosolic virus is a single stranded RNA virus. The virus is surrounded by an envelope with a lipid membrane. Inside the envelope are matrix proteins, integrase, protease, reverse transcriptase and the RNA genome. All viruses contain three proteins necessary for their survival; one for replication, one for packaging and delivering it to more host cells and a protein that modifies the function or structure of the host
Viruses are tiny organisms that contain nucleic acid encased by a protein coat. Some are enclosed by an envelope of fat and protein molecules. This organisms cannot grow, reproduce or carry out their functions without a host cell. A virus invades living cells and uses their chemical properties in order to keep itself alive and reproduce. As they don’t have ribosomes they are not able to synthesise proteins and they are also unable to generate or store energy in the form of ATP. Therefore, they use the ribosomes of host cells to translate viral messenger RNA into viral proteins, and drive their energy and all other metabolic functions from the host cell. They also depend on the host cell for basic building materials, such as amino acids, nucleotides,
The idea is to use a proteasome inhibitor, in this case, bortezomib, to selectively inhibit Valosin-Containing Proteins (VCP) that promotes accumulation of immature CFTR in the ER and partial rescue of functional chloride channels (Vij, Fang, & Zeitlin, 2006). All of this seemed very complicated, but what they found was that bortezomib could rescue the ΔF508-CFTR from ERAD and resulted in the appearance of mature CFTR. However, the researchers expressed concern about using proteasomes as a therapeutic target because proteasomes can be a risk as they are involved in the generation of various conditions. The biggest challenge is that ERAD has a particular role to serve as the screener for folded proteins. Therefore, should we inhibit
ubiquitin-proteasome pathway in normal and disease states. Journal of the American Society of Nephrology. 17,1807-1819.
The de-ubiquitinase (DUB) will cleave this precursor into free monomer ubiquitin molecules and can be activated and attached to the target protein through ATP dependent process called ubiquitination with the help of activating enzyme E1, conjugating enzyme E2, and ligase E3. Through forming (iso)-peptide, thioester, or ester bond between carboxyl groups of C-terminal glycine 76 on ubiquitin and the ε-amino group of the lysine, cysteine, serine/threonine on the substrate, respectively, the poly-ubiquitin chain is formed [3]. Based on the different internal Lysine (Lys6, Lys11, Lys27, Lys29, Lys33, Lys48, and Lys63) and on the proximal ubiquitin, the (iso)-peptide bond can be form with another ubiquitin, distal mono-ubiquitin [4, 5]. Consequently, seven conventional poly-ubiquitin chains resulting in different 3-dimentional shapes explaining its different characteristics inherited upon binding to the target protein [5, 6]. With ranging more than 500 putative E3 ligases exist in human, the E3 ligase will tag the poly-ubiquitin chain to the target protein with high specificity
The KLHL3 gene (Kelch like family member 3) creates a protein that works in conjunction with proteasomes to degrade unwanted proteins via an ubiquitin-proteasome system. KLHL3 is mainly expressed in the cerebellum and the distal collecting tubule in the kidneys (3). is Though expressed in the KLHL3 protein has a N-terminal BTB domain, a C-terminal that has Ketch-like repeats, and a BACK domain, forming a conformation that is a bladed beta propeller structure (1). The protein produced by this gene is part of a complex (E3 ubiquitin ligase), which functions to indicate damaged and additional proteins by labelling these with ubiquitin, which is the tag later recognized by proteasomes for breakdown (4). This labelling is possible with the
This demonstrates the urgency and need to study these family of proteins in effort to treat
Ubiquitin is composed of 3 enzyme units, which facilitate the breakdown of proteins into amino acids, these are E1: ubiquitin activating enzyme, E2: ubiquitin-conjugating enzyme and E3: ubiquitin-protein ligase. Once targeted proteins are marked by ubiquitin for degradation, a proteasome will digest the protein and break it down into its constituent amino acids, while the ubiquitin is cleaved off and recycled for future use.
Previous studies have suggested that K63 ubiquitination is associated with anti-apoptotic protein trafficking pathways. Figure 1 addresses whether K63 ubiquitination is accomplished by the TRAF6 E3 ligase. An immunoblot of p53 was used for U2SO cells in a Ni-NTA assay to determine if K63-linked ubiquitination of p53 was associated with TRAF6. U2SO cells were used because of their high proliferation rates. Flag-TRAF6 and p53 were included in the western blot as controls for this assay. Ubiquitin was tagged with histidine and TRAF6 was tagged with the Flag antibody to assess protein to protein interactions. This assay shows ubiquitination of p53 in the presence of His-Ub and Flag-TRAF6 indicating that K63 linked ubiquitination of p53 depends on TRAF6. To determine if specifically, K63-linked ubiquitination occurs through TRAF6 the authors assessed whether TRAF6 promotes K48-linked ubiquitination of p53 and proteasomal degradation. An immunoblot for HA in a Ni-NTA pull-down assay was generated to assess if ubiquitination and proteasomal degradation occurs at K48 and K63 by TRAF6. HA-p53 and Flag-TRAF6 in U2SO cells were used to show protein-protein interaction. A
The overall objective of the project is to identify the proteins that interact with EccA1 using a yeast two-hybrid assay test and to characterize the particular regions of the proteins that interact. The TB DNA was isolated from a PCR colony to be used as a template for a PCR reaction. An agarose gel was created and used for electrophoresis of the DNA. A UV illuminator displayed the image of the agarose gel. Use of the analytic software such as 4Peaks, the NCBI tools BLAST and CDD, TUBERCULIST, and CLUSTAL Omega. As a result, the identity of the unknown protein was discovered. Information about the protein, such as the protein’s genes that interacted with EccA1, particular structure and function, and protein alignment, were gathered from these softwares as well. The outcome of the experiment is expected to result in the
Moreover, further deletion mapping could be performed to narrow down the specific sequence within the third SIRPT of sacsin that binds JIP3.
Viruses are biological agents that are extremely small and highly infectious. It possesses the ability in infecting all cell types, from complex eukaryotes such as plants and animals, to microorganisms including archaea and bacteria. [1] However, it could only rely on infecting a host cell for viral replication, which when infecting a host cell it incorporates its genetic materials into the host cell DNA and uses the host’s cellular component for replication, such that the cell produces viral proteins and genetic materials for assembling new viron instead of its usual products. [2]