Both prokaryotic and eukaryotic cell quickly responds to stress or damaging atimuli. In response to a range of different stress , including heat shock , nutrients deprivation, and metabolic disruption, cells synthesize about two dozen different proteins (called stress proteins) .The most thoroughly studied stress is heat shock, in which a sudden increase in temperature includes the synthesis of a group of proteins. Genes that are responsible for the synthesis of heat shock proteins are among the most evolutionarily conserved genetics system s known. They are very similar in amino acid sequence in both prokaryotes and eukaryotes. Heat shock proteins accumulate to very high level in stress cells, accounting for as much as 15% of the total protein in E.coli.
The function of several of the heat shock protein is beginning to be understood. Most of these proteins are synthesized at low levels under normal growth conditions and play a vital role in protecting the cell from the damaging effects of heat and other stresses. The heat shock proteins hsp70 and hsp60 (the number refers to the molecular weight of the protein times 1000) are involved in assembly or disassembly of protein complexes.
Hsp70 is involved in translocating certain proteins trough intracellular membranes and binds to DNA replication complexes. Hsp60 has been found to interact with steroid hormone receptors. In plats hsps60 interacts with what may be the most abundant protein in the biosphere, ribulose-1,5-bisphosphate carboxylase-oxygenase, an enzyme that fixes CO2 in chloroplasts.
An amazing example of the use of heat shock proteins for protection in found in the desert- dwelling ant Cataglyphis bombycina , which is perfectly suited for life in the Sahara desert. Cataglyphis bombycina anticipates the high temperature of up to 1400 F found in the desert sand by producing heat shock proteins in abundance, even when in underground nests. These proteins seem to protect them to their natural conditions, grinding them up , and finding copious quantities of the heat shock proteins : a primitive strike against the searing temperatures.
Invading organisms also can produce stress proteins in the host. This can be detrimental because some of these proteins in the host. This can be deter mental because some of these proteins are very similar to the host’s stress proteins and create an autoimmune disease in the host’s organism. For example, researchers have shown that the hsp60 proteins from tuberculosis bacterial and human cells are sufficiently similar that they are they both recognized by antibodies from a tuberculosis patient.. Thus , a bacterial invasion may induce the body’s immune system to make antibodies to the stress protein of the bacteria, and these antibodies to the stress proteins of the bacteria, and these antibodies may also attack some of the body’s own vital proteins. It is believed that this may be the development process of some forms of chronic rheumatoid arthritis, which is an inflammation of the synovial membranes of joints.
The function of several of the heat shock protein is beginning to be understood. Most of these proteins are synthesized at low levels under normal growth conditions and play a vital role in protecting the cell from the damaging effects of heat and other stresses. The heat shock proteins hsp70 and hsp60 (the number refers to the molecular weight of the protein times 1000) are involved in assembly or disassembly of protein complexes.
Hsp70 is involved in translocating certain proteins trough intracellular membranes and binds to DNA replication complexes. Hsp60 has been found to interact with steroid hormone receptors. In plats hsps60 interacts with what may be the most abundant protein in the biosphere, ribulose-1,5-bisphosphate carboxylase-oxygenase, an enzyme that fixes CO2 in chloroplasts.
An amazing example of the use of heat shock proteins for protection in found in the desert- dwelling ant Cataglyphis bombycina , which is perfectly suited for life in the Sahara desert. Cataglyphis bombycina anticipates the high temperature of up to 1400 F found in the desert sand by producing heat shock proteins in abundance, even when in underground nests. These proteins seem to protect them to their natural conditions, grinding them up , and finding copious quantities of the heat shock proteins : a primitive strike against the searing temperatures.
Invading organisms also can produce stress proteins in the host. This can be detrimental because some of these proteins in the host. This can be deter mental because some of these proteins are very similar to the host’s stress proteins and create an autoimmune disease in the host’s organism. For example, researchers have shown that the hsp60 proteins from tuberculosis bacterial and human cells are sufficiently similar that they are they both recognized by antibodies from a tuberculosis patient.. Thus , a bacterial invasion may induce the body’s immune system to make antibodies to the stress protein of the bacteria, and these antibodies to the stress proteins of the bacteria, and these antibodies may also attack some of the body’s own vital proteins. It is believed that this may be the development process of some forms of chronic rheumatoid arthritis, which is an inflammation of the synovial membranes of joints.
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