Research Strategy
A. Significance
Intracellular trafficking is an essential cellular communication process in which membrane vesicles carrying lipids, proteins, and nucleic acids are taken up and transported through endosomes to lysosomes (termed endocytosis) and vesicles carrying macromolecules are delivered to the plasma membrane and outside of the cell (exocytosis) {Oka, 2005 #5437}. Uptake of external particles through endocytosis is required for prolific growth and differentiation. For example, uptake of transferrin provides iron necessary for growth and parasitism of the parasite Plasmodium falciparum {Rodriguez, 1986 #5445}. In contrast, the synaptic release of neurotransmitters, including dopamine and serotonin exemplifies
…show more content…
By sharing only the N-terminal EH domains and CC region with ITSN1 plus a proline-rich (PR) region, Pan1 has a role in endocytosis and the organization of cortical actin through interactions with additional partner proteins, including EH proteins Ede1 and End3 {Wendland, 1998 #5492;Huang, 2007 #5510;Miliaras, 2004 #5491}. Pan1 homologs were identified from Candida species and Magnaporthe oryzae (Mo), but not Cn, indicating that Pan1-mediated endocytic trafficking is not universal among fungi ({Martin, 2007 #5481}, ZG Zhang and P Wang, unpublished data).
Cn is an encapsulated basidiomycetous fungus infecting both immunocompromised and healthy individuals causing life-threatening meningoencephalitis {Mitchell, 1995 #878}. It produces virulence factors including melanin, the polysaccharide capsule, and extracellular ureases and phospholipases {Kozel, 1995 #1696;Buchanan, 1998 #2608;engeler, 2000 #3148}. Previous studies showed that secretory transport is important in virulence {Rodrigues, 2009 #5368;Jesus, 2009 #5368} and that Cn contains proteins with a conserved function in exocytosis, such as Sav1, Sec6, and Sec14 {Yoneda, 2006 #5408;Panepinto, 2009 #5385;Chayakulkeeree, 2011 #5686}. We identified cryptococcal intersectin 1 (Cin1) as a novel endocytic adaptor protein that is important not only in intracellular transport but also in growth and virulence
Cryptococcus neoformans (Cn) virulence depends on the active transport of vesicles that contain melanin and capsule precursors, proteinases, and other macromolecules. We previously found that the Cn intersectin protein Cin1 regulates intracellular trafficking critical for growth and virulence and that Cin1-S isoform confers a marked survival advantage in the CNS of a murine model of cryptococcosis. In addition, we found that the expression of extracellular RNAs (exRNAs) including small RNA (sRNA), mRNA, and long noncoding RNA (lncRNA) was significantly differentiated among cin1, CIN1-S, and wild type stains. Further investigation of these observations could promote our understanding of Cn propensity for the host CNS and the virulence
The two body organ systems involved in gas exchange are the respiratory and cardiovascular systems. O2 and CO2 cross the cell membrane via simple diffusion. Because cells all throughout the body require oxygen and the removal of carbon dioxide, this simple method of diffusion is the best way to transport such small molecules over a large area as efficiently as possible.
3. Explain your prediction for the effect Na+ Cl- might have on glucose transport. In other words, explain why you picked the choice that you did. How well did the results compare with your prediction?
[4] – Frank Schluenzen et al, Structure of Functionally Active Small Ribosomal Subunit at 3.3A Resolution
Explain the effect that increasing the Na+ Cl- concentration has on osmotic pressure and why it has this effect. How well did the results compare with your prediction?
There are many parts of a cell, they all have specific duties, and are all
What happens to the urea concentration in the left beaker (the patient)? It mixes with the water to balance out the structure.
The purpose of these experiments is to examine the driving force behind the movement of substances across a selective or semiperpeable plasma membrane. Experiment simulations examine substances that move passively through a semipermeable membrane, and those that require active transport. Those that move passively through the membrane will do so in these simulations by facilitated diffusion and filtration. The plasma membrane’s structure is composed in such a way that it can discriminate as to which substances can pass into the cell. This enables nutrients to enter the cell, while keeping unwanted substances out. Active
To study the effects of hypotonic, hypertonic and isotonic solutions on plant and animal cells.
The endoplasmic reticulum (ER) is an essential organelle that is a major place for the biogenesis of cellular components including proteins, lipids, and carbohydrates and internal calcium storage. ER is primarily responsible for protein translocation, protein folding and protein post modification. Proper folding of protein in the ER is accomplished with the aid of ER resident proteins or enzymes such as chaperones. Binding of chaperones to
If the solution in the left beaker contained both urea and albumin, which membrane(s) could you choose to selectively remove the urea from the solution in the left beaker? How would you carry out this experiment?
The Transport of Substances Across the Plasma Membrane The plasma membrane or, the cell surface membrane, is made almost entirely of protein and lipid. The plasma membrane controls the movement of substances into and out of a cell. It is partially permeable so some substances cross more easily than others.
The cell membrane consists of eight distinctive parts that each have their own unique structure and function. The phospholipid bilayer is an integral part of the cell membrane because it is the external layer of the cell membrane and composes the barriers that isolate the internal cell components and organelles from the extracellular environment. It is composed of a series of phospholipids that have a hydrophobic region and a hydrophilic region. These regions are composed of the hydrophilic heads and the hydrophobic tails of the phospholipids, this organization of the polar heads and nonpolar tails allows the heads of the cell to form hydrogen bonds with water molecules while the tails are able to avoid water. The phospholipid bilayer also has many important functions within the cell, it gives the cell shape, provides protection, and it is selectively permeable which allows it to only let very specific molecules pass through its surface. The phospholipid bilayer is an important structure because it prevents harmful and unwanted molecules from entering the cell and isolates organelles which helps to maintain the internal environmental homeostasis of the cell.
Overexpression of the HEPN domain in HeLa cells following three hours of starvation indicates that sacsin plays a key role in lysosomal transport due to the reduced efficiency of perinuclear lysosomal clustering. HEPN’s property of dimerizing may be disrupting the function of with full-length sacsin by preventing endogenous sacsin from dimerizing within the cell. Thus, dimerization may be essential to sacsin’s function, particularly for binding JIP3, which is necessary for lysosomal transport7. HATPase 3 overexpression may be occupying JIP3 binding, but was not found to disrupt lysosomal localization following starvation, perhaps due to the truncated size of this deletion construct.
The class results displayed in Table 2 indicate which of the four ‘prey’ inserts produce proteins able to undergo protein-protein interactions with each strain of Bub1B. A high Leu, Trp, Ade colony count indicates that protein-protein interactions occurred, allowing for yeast growth. From Table 2, BUB3 interacts with strains Bub1B (186-613), Bub1B (324-667) and Bub1B (328-1052). CDC20 interacts with strain Bub1B (186-613). Ppp2rc interacts with Bub1B (328-1052), and Bub1B (588-1052). Zfp207 interacts with no strains of Bub1B, according to Table 2.