HW 3 cell Biology

.docx

School

CUNY John Jay College of Criminal Justice *

*We aren’t endorsed by this school

Course

315

Subject

Biology

Date

Jan 9, 2024

Type

docx

Pages

Uploaded by pauliono190712

Name: Arleny Paulino BIO 205 Homework Assessment Form for Paper 3 - Mashukova et al. Instructions: Responses must be typed . Papers are provided on Blackboard and students are responsible for reading and completing this assignment and then submitting this form via the appropriate Blackboard submission link by the due date. Late assignments will be penalized. Plagiarism of any kind will result in an automatic zero for the entire assignment. Write out the paper’s reference in APA format: Mashukova, A., Spehr, M., Hatt, H., & Neuhaus, E. M. (2006). beta-Arrestin2-Mediated Internalization of Mammalian Odorant Receptors. The Journal of Neuroscience , 26 (39), 99029912. https://doi.org/10.1523/jneurosci.2897-06.2006 1. What is the main focus of the paper? In this paper, it is focusing to understand the mechanist development of deodorant receptor by the Protein arrestin2 in mammalian. This protein plays a role in a factory system. The Ors helps to deceit the different odor in the molecules which are present in the environment. Knowing that this is import regulator G- protein coupled receptor (GPCP) signaling. , 2. What were the main findings? One of the main found is that arrestin2 promotes OR’s absorption via clathrinid coated pit. OR uptake is influence by the presence of some amino acid residues in the receptor. Also, that the internalized receptor is degraded by targeting some lysosomes. 3. What is signaling desensitization, and what is the mechanism of desensitization described in this paper? In the paper, it’s described the signaling deserialization as action where the cell become less response to certain stimulus. In the mechanism, it is talking about mammalian odorant receptors with the protein. Arrestin2. ORs are G protein-coupled receptors (GPCRs) that bind to odor molecules, triggering a pathway that leads to odor perception. Long term exposure to odor molecules can end in sensitization of the OR signaling pathway, limiting the cell's capacity for recognizing the odor. Arrestin2 is a protein that attaches to engaged GPCRs and triggers their internalization into the cell, leading in signaling pathway desensitization. According to the study, Arrestin2 promotes the internalization of ORs in response to extended odor exposure, as result in a decrease in the cell's capacity to detect the odor. ‘ 4. There are two ways you can label an olfactory receptor neuron: 1. Using the promoter to drive GFP, or 2. Fusing GFP to the receptor. In figure 1, how do you know based on the images whether it is the first way or the second way?

The olfactory receptor cell has been labeled in a second way, by fusing GFP to the receptor. This is because confocal microscope pictures demonstrate that the GFP signal is confined to intracellular vesicles that different levels of granularity with transferrin, but it is coming from the lysosomal protease cathepsin D. This suggests that the activation, where the receptor undergoes cellular uptake. Then is locate in intracellular vesicles. The discovery of OR2AG1-GFP migration from the cellular membranes to intracellular compartments after amylbutyrat stimulation (Figure 1) shows that the GFP is localized to the receptor and traffics with it. 5. BRET is a way to study protein-protein interactions. Describe BRET, and come up with one additional way that you could study if protein A interacts with protein B. Bret Assay is considering a noninvasive technique that helps with the transfer of energy from RLuc. This involves diffusion processes in proteins. The foundation for it is frequency energy transfer, which occurs only when two proteins are close to one another. The energy travels from a donor enzyme to an acceptor fluorescent protein. Proteins A and B interact with each other. Using an antibody that selectively targets one of the proteins, a protein is pulled down from a group of proteins. If the pulled-down molecule interacts with another protein, the other protein will be dragged down and detected using spectrometry. It can be employed to explore protein-protein interactions under various circumstances, revealing the identification and stoichiometry of protein complexes. 6. Describe the site directed mutagenesis that was performed in Figure 4 and what they were able to show. This figure describes how the mutation of the gene and how the beta-arretin2 receptor plays an important role in the mammalian odorant receptor's process. The cause of amino acid mutations in the mammalian odorant receptor OR2A1's N terminal intracellular domain. This domain contains essential beta-arrestin2 binding sites. They created the R72A/R77A twin mutant by first altering the protein residues Arg-72 and Arg-77 to alanine. They discovered that despite the usual position and activity on the plasma membrane, a double mutant could not be absorbed by beta-arrestin2. Based on these findings that arrestin2 seems to have a significant part in the passage of odorant sensors into mammalian cells. 7. If you wanted to study olfactory signaling, what is another gene you could mutate and what would you predict to show? What experiment would you do to determine the effect of the mutations ‘ Another gene we can mutate will be of olfactory signaling is the G protein could be the receptor kinase 3 (GRK3) which one plays a role in the regulation of receptor (OR) signaling by promoting the internalization of (OR) in the mechanics arrensti2 like the receptor PCP signaling with the G protein. To experiment with the gene the OSN could be isolated from the olfactory system epithelium of the mice and then apply the gene mutation to OR signaling. GRK3 mutant OSNs would be loaded with a calcium- sensitive dye and subjected to a variety of odorants in this experiment. Calcium imaging would be utilized to track changes in intracellular calcium concentration in response to odorant stimulation, which is a proxy for OR activation.

Your preview ends here

Eager to read complete document? Join bartleby learn and gain access to the full version