Tissues Specific Roles For Two Grp170 Chaperones Loci

Wischusen, William, Jolissaint, Ann, Reiland, Jane, and Pomarico, Steven. 2012. Biology 1208/1209: Biological Laboratories for Science Majors. Hayden McNeil, Plymouth,

If necessary, use the back of the exam pages for the rest of your answers. Do not use other sheets of paper. Please write legibly; if I cannot read your answer, I will count it wrong.

sHSPs are a ubiquitous class of chaperones found across all kingdoms of life. sHSP range in size from 12-42 kilo Daltons in large oligomers of 12 to >32 subunits and the structure is homologous across all species. The sHSP monomer consists of three domains: a disordered N-terminal arm, a beta-sandwich α-crystallin domain, and a flexible C-terminal extension. The N-terminal domain is the most variable region with little conservation between species. Experimental evidence also suggests N-terminal involvement in substrate binding and protection. The α-crystallin domain is the most highly conserved region and adopts a β-sandwich conformation composed of 7 to 8 anti-parallel β-strands (Basha et al, 2012). The C-terminus contains an I-X-I motif, which helps to satblizie the oligomeric form of the sHSP (Basha et al, 2012).

For the methods used in this experiment refer to the following from UFV BIO 202 Lab #2: Investigation of Heat Shock Protein Gene Expression using Western Blotting (2017).

Proteins are primarily considered to have one primary function to serve its role in an organism, however studies have observed to have multiple functioning proteins known as moonlighting proteins (Khan et al. 2014). Moonlighting proteins along with primary functions, have secondary functions that are not related to the primary function and does not correlate to the primary or other functions (Khan et al. 2014). The multifunctional proteins play essential roles in carrying out biochemical functions which aids in the cell growth but are not caused by gene fusion and multiple RNA splice variants (Amblee et al. 2015). The discovery of moonlighting proteins was first discovered by Piatigorsky and Wistow while observing crystallins (Khan et al. 2014). Crystallins, are structural proteins that are found in the eye lens that exhibit enzymatic activity to make the lens itself (Khan et al. 2014). Crystallin has a primary function to help form the lens of the eye by acting as a structural protein (Amblee et al. 2015). Besides enzymatic activity, crystallin was observed in other mammals to have secondary functions such as metabolic functions which are helpful in prokaryotic (Khan et al 2014). Most moonlighting proteins are characterized as cytosolic enzymes and chaperons, or in other words helping proteins (Amblee et al 2015). The multifunctional proteins or moonlighting proteins can also be identified as receptors, channel proteins and ribosomal proteins (Khan et al. 2014). Due to the

The amino acid sequences derived from decoding the mRNA determines a protein's final conformation, helper proteins aid the newly formed polypeptide with its folding to achieve a proper functional shape. These molecular chaperones are essential as the cytoplasm is often filled with new polypeptide chains and thus these accumulation of polypeptide chain might accumulate together and fold into a non-function shape. Example of well studied chaperones from E.Coli are DnaK, DnaJ, GroEL and GroES. And GrpE.

Proteins are biological macromolecules made from smaller building units called amino acids. There are 20 natural occurring amino acids which can combine in various ways to form a polypeptide. There are four distinctive levels of protein structure: primary, secondary, tertiary and quaternary. The primary structure of a protein is important in determining the final three dimensional structure and hence the role and function of a particular protein, both in the human body and in life around us. The secondary structure of a protein can fall into two major categories; α-helices or β-sheets, other variants also exist such as β-turns {{20 Brändén, Carl-Ivar, 1934- 1991}}. The precise folding or these secondary structures into a three dimensional shape is known as the tertiary structure of a protein and multiple polypeptides bound together via covalent and non-covalent bonds forms the complex quaternary structure of a protein.

These proteins differ depending on their function in the cell, but often prevent misfolding of nascent protein, and assist in refolding of the misfolded proteins. Protein folding is dependent on the amino acid sequence within the polypeptide chain that is synthesized from the DNA strand in the ribosome.2 Upon release from the ribosome, the polypeptide chain undergoes a series of conformational changes based on the amino acid sequence to produce a functional protein structure. The assembled native protein is directed to the ER via vesicle

ALS is a neurodegenerative disease that is caused by many contributing factors; one such factor is the aggregation of TDP-43 protein, characterized by ubiquitinated proteins that build up in abnormal intra-neuronal inclusions in hippocampus, neocortex, and spinal cord in the individuals affected with ALS. Inclusions may arise from a cellular attempt to group accumulated proteins preventing their obstruction with normal cell function. Presence of these inclusion bodies confer cytotoxic effects that play a part in neuronal cell damage, which causes oxidative stress and stimulates apoptotic pathways destroying the motor neurons. In this project we have tried to find a probable molecule which can bind to TDP-43 and prevents its aggregation by preventing

The endoplasmic reticulum (ER) stress has emerged as one of the major pathophysiological mechanism of various diseases. It is a multifunctional cellular organelle and it is responsible for protein synthesis, folding, trafficking, processing transmembrane proteins and is also known as a primary sensor for cellular stress (2). In order for the ER proteins to be folded properly, there must be a balance between the ER proteins and the amount of folding capacity for it to process. However, the ER homeostasis may be disrupted which could cause the accumulation of unfolded and misfolded

This folding describes the arrangement of the amino acids. The shape of the acids is held in place by the hydrogen bonds. A hydrogen bond is a dipole-dipole interaction between a hydrogen atom and an electronegative atom. The hydrogen bonds are important because if they didn’t hold the structure of the amino acids in place, there would be no backbone for the protein.

Heat shock protein 90 (Hsp90) is a 90 kilo Dalton, ubiquitously expressed molecular chaperone that is required for plays a critical role in various biological processes including cellular survival, regulation of cell cycle, steroid and other signaling pathways. Although Hsp90 was initially discovered as a protein whose expression increases upon heat stress, it is one of the most abundant chaperone in the cytoplasm of the eukaryotic cells encompassing 1-2% of the total cellular protein under normal physiological conditions. The most common homologs of Hsp90 present in the cytoplasm of mammalian cells are the inducible Hsp90α and the constitutively active Hsp90β. Additionally; Hsp90 homologs Trap1 and Grp94 are present in mitochondria and endoplasmic reticulum. Hsp90 protein exists as a homo dimer with each promoter having the following functional domain architecture. They are, (1) the N-terminal ATP binding domain (NTD) that binds to co-chaperones such as cdc37 and p23 as well as drugs such as galadanamycin, (2) the middle domain (MD) with a catalytic loop needed for the binding of clients and co-chaperones such as Aha1 and (3) the C-terminal dimerization domain (CTD) with a conserved EEVD motif that interacts with cofactors

Gene expression is the ability of a gene to produce a biologically active protein. This process is regulated by the cells of an organism, it is very important to the survival of organisms at all levels. This is much more complex in eukaryotes than in prokaryotes. A major difference is the presence in eukaryotes of a nuclear membrane, which prevents the simultaneous transcription and translation that occurs in prokaryotes. Initiation of protein transcription is started by RNA polymerase. The activity of RNA polymerase is regulated by interaction with regulatory proteins; these proteins can act both positively, as activators, and negatively as repressors. An example of gene regulation in cells is the activity of the trp operon. The trp

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

Proteins are vital components of all living organisms. These macromolecules are identified as large molecules composed of one or more chains of amino acids. There are twenty different amino acids that can be used to create various types of proteins. Specific sequences of amino acids in a chain is determined by DNA coding of the cell. An amino acid’s sequence is essential since it determines the overall structure and function of a protein. There are several different types of proteins such as enzymes, transport, storage, signal, structural, motor, receptor, gene regulatory, and special type/purpose proteins. Proteins also take part in biological processes, including cell growth, defense, movement, and regulation of organs.