Nobel Prize Awarded to Randy W. Schekman, James E. Rothman, and Thomas C. Südhof

[1] – Molecular Cell Biology, 7th edition 2012, Harvey Lodish, Chris A. Kaiser, Anthony Bretscher, et al. Macmillian Higher Education.

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

The cell is the basic unit of life in eukaryotic organisms. The inside of the cell is comprised of multiple subunits called organelle that all function together to maintain homeostasis and function. Each individual organelle is assigned a specific task and purpose for the cell. These tasks and purposes can range from structural support all the way to the disposal of malfunctioning organelle.1 Similarity to a machine, if one part stops functioning to full potential, serious if not fatal consequences can be faced. A shining example of the effects of a malfunctioning organelle occurs in Tay-Sachs disease. Tay- Sachs disease is a lysosomal disorder that is caused by a faulty lysosome.1 Recent studies and research have been investigating the causes and pathways Tay-Sachs disease with great success, which is amazing news for the scientific community.

Lysosomes are specialized vesicles that are created by the Golgi body. Their role is to digest any worn out, excess or unwanted bodies within the cell. This could include bacteria or viruses as well as mitochondria which are no longer effective. To do this they contain an

A vesicle is bubble like membranous structure that stores and transports cellular products and digests metabolic waste in a cell. (Biology Online, 2008)

. The F (fusion) glycoprotein is responsible for membrane fusion such as viral penetration and syncytium formation.

Cystic fibrosis (CF) is a progressive condition in which epithelial exocrine glands are obstructed (Howe, 2001). Whilst many organs and bodily systems are disrupted by CF, the lungs and gastrointestinal organs are predominantly affected; it is also most common amongst the Caucasian population due to the autosomal recessive gene (Quitter et al., 2003 cited in Wolfe & Mash, 2006, pg 514). The faulty gene effects the production of cystic fibrosis transmembrane conductance regulator protein, which is responsible for the formation of molecular tunnels which monitor the movement of salts and water from the cells (Hopkin, 2010 pg 4).

The Nobel Prize in Physiology or Medicine 2001 was awarded jointly to Leland H. Hartwell, Tim Hunt and Sir Paul M. Nurse "for their discoveries of key regulators of the cell cycle".

One system detects defects in the cytosolic parts of the CFTR while the other detects defects within the endoplasmic reticulum membrane. It is apparent that ubiquitylating proteins work with specific factors in order to detect misfolding. For example, Hsp70 detects mutations in the cytosolic regions of the CFTR. It is suspected that Hsp70 keeps the CFTR soluble until the E3 ligase CHIP binds with it. The complex that forms between these two redirects the CFTR to the degradation pathway. Derlin-1 is involved with detecting defects in the endoplasmic reticulum membrane and is involved in the retro-translocation of CFTR from the endoplasmic reticulum so that it can be send to the proteasome for degradation [20]. If the CFTR protein is folded correctly within the endoplasmic reticulum, then it is sent to the Golgi apparatus. The coat protein complex II (COPII), which is found within the ER membrane, helps to maintain the correct CFTR structure and location, conformation, and protein-protein interactions as this occurs. Final processing for the CFTR is carried out within the Golgi, as the CFTR replaces a mannose-enriched side chain with a mature complex oligosaccharide side chain. After this is completed, the CFTR is moved to the apical membrane where it has a half-life of 12 to 24 hours. If a CFTR is functioning poorly within the membrane, then it can be recognized by Hsc70 and then

Some of these adapter proteins also interact with a docking protein (SNARE) on the plasma membrane and assist FL-myoVa to act as a tether for releasing cargo4-6. For example, Gran A/B directly binds to syntaxin 1a, a SNARE protein responsible for docking the granule at the plasma

Good morning. This is Larry Lysosome here. I work at The Cell Corporation. My job here at Cell Co. is to recycle the other malfunctioning parts of the cell and return their nutrients back into the cell. I write to you because I am aware that you will soon be firing some employees here at Cell Co. and wanted to inform you that Cell Co. would be a complete mess without me (no pun intended). I'm a vital part of the corporation and it would be nearly impossible for the other organelles as well as you Mrs.Eukaryote to work properly without me. So I ask that you take a moment to listen to me and consider what I have to say.

Cells share many common features but have adapted over billions of years in a wide array of environments, to provide a variety of functional roles.

On Oct. 3, the 71-year-old molecular cell biologist stood amongst a sea of reporters and colleagues at the Tokyo Institute of Technology (TITECH) and echoed these words that he often shares with his students. Ohsumi won this year’s Nobel Prize in Physiology or Medicine for nearly three decades of fundamental research in autophagy – the process by which cells recycle their own contents. On Dec. 10, Ohsumi will stand on stage in Stockholm, this time in front of the global scientific community, to accept his award and join the ranks of other Nobel laureates.

Exosomes are membranous vesicles enclosed in lipid bilayers with diameter of 30-100nm and are responsible in carrying cytoplasmic proteins such as Rab proteins and actin-binding proteins and signal transduction molecules such as G-proteins and protein kinases, as well as some heat-shock proteins like Hsp70 and tetraspanins like CD9 [5-30]. Exosomal proteins can directly represent the specific profiles of their cells of origin, for

Ultimately, PI3P plays a crucial localization response to facilitate fusion at the last step of double-membrane autophagosome synthesis. Binding between Vps34 and Beclin-1 is enhanced by Ambra-1 (activating molecule in Beclin1-regulated autophagy protein-1), Bif-1 (Bax interacting factor-1), and UVRAG (ultraviolet radiation resistance-associated gene) whereas Bcl-XL, Bcl-2 and Rubicon (Run domain Beclin-1 interacting cysteine-rich containing protein) inhibits this interaction. Another stress induced transmembrane protein is vacuole membrane protein 1(VMP1) which interacts with Beclin-1 to induce autophagy. A couple of ubiquitin-like conjugation system gets involved during autophagosome elongation through a chain of events. Atg 12 interacts with Atg 7 (E1 ubiquitin-like activating enzyme), following which Atg12 binds to Atg10 (E2-like ubiquitin carrier), thereby linking Atg12 to Atg5; then, Atg16 dimers gets attached to this complex resulting in phagophore expansion. The Atg5-Atg12-Atg16 complex helps in the growth of the nascent edges of the phagophore. This trimeric conjugation drops out when the phagophore finally matures into the autophagosome. A second ubiquitin- like system is involved in microtubule associated protein light chain 3 (LC3, mammalian homolog of yeast Atg8) processing.Atg4 cleaves LC3 to an active intermediate LC3I by conjugating with E1-like Atg7 through an ATP dependent