Human growth hormone: Difference between revisions
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'''Glycosylation'''<br/> | '''Glycosylation'''<br/> | ||
Glycosylation helps distinguish between different variants and isoforms as it works as an ID cards for proteins. These carbohydrates are specific to each forms and are recognized by the associated hgH receptors. Though still being a relatively unknown mechanism in hgH, studies have shown that one isoform in particular, a 22kDa variant was identified and discovered due to the specific carbohydrates linked to its polypeptide chain (M.Kirstein 1992). | Glycosylation helps distinguish between different variants and isoforms as it works as an ID cards for proteins. These carbohydrates are specific to each forms and are recognized by the associated hgH receptors. Though still being a relatively unknown mechanism in hgH, studies have shown that one isoform in particular, a 22kDa variant was identified and discovered due to the specific carbohydrates linked to its polypeptide chain (M.Kirstein 1992). | ||
==Secretion Mechanism== | ==Secretion Mechanism== | ||
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In order to facilitate this behavior as a hormone somatotropin binds to two receptors on the outside of a cell known as Human Growth Hormone Binding Proteins (hGHpb). Once the Human Growth hormone binds both receptors (first one, then the second), it causes a shift in the receptor protein, which in turn causes an internal signaling cascade. This cascade is how somatotropin is able to effect cell growth and function. In addition it can cause the release of other growth factors, like Insulin Growth Factor. | In order to facilitate this behavior as a hormone somatotropin binds to two receptors on the outside of a cell known as Human Growth Hormone Binding Proteins (hGHpb). Once the Human Growth hormone binds both receptors (first one, then the second), it causes a shift in the receptor protein, which in turn causes an internal signaling cascade. This cascade is how somatotropin is able to effect cell growth and function. In addition it can cause the release of other growth factors, like Insulin Growth Factor. | ||
Examples : | |||
For Growth : | |||
HGH is especially important for the growth of cartilage and bone. It’s efficiency will increase even more during the adolescent years when it is more produced. | |||
Insulin-like growth factor-1 binds to its receptor, IGF-1R, on the cellular surface and activates a tyrosine kinase-mediated intracellular signaling pathway that phosphorylates various proteins intracellularly leading to increased metabolism, anabolism, and cellular replication and division. Furthermore, it acts to inhibit apoptosis of the cell, thus prolonging the lifespan of existing cells. The net result is to encourage the growth of tissue and to create a hyperglycemic environment in the body. | |||
==Inhibitors== | ==Inhibitors== | ||