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A snapshot of the summary - Evolutionary Developmental Biology
1. Evolutionary conservation of hormones and enzymes
What is the difference between diabetes type I and type II?Type I:
- Hyposecretion of insulin
- Insulin dependent
- Juvenile onset
- Late onset (adult)
- Insensitive to insulin
- Managed by exercise and diet
Peptide hormones are prohormones. What is meant with this?It means that the hormones are large precursor hormones, they need to be processed before being bioactive.
How become peptide hormones bioactive?
- Endo- and exoproteolysis (cleavage into smalles fragments)
- Modifications (α-amidation, acetylation, phosphorylation)
What does dysregulation of insulin/glucagon cause?Dysregulation of insulin/glucagon leads to obesity. Neuropsychiatric diseases are often comorbid with obesity / problems with glucose regulation.
How are peptide hormones synthesized?It is a regulated secretory pathway, this means that synthesis and release is on demand.
- Proteins require a signal peptide
- Synthesis via ER, to Golgi and exocytosis via large-dense core vesicles via membrane fragments (endosomes)
What is a constitutive secretory pathway?A constitutive secretory pathway is continuous, the proteins do not have a signal peptide
What happens during protein folding in insulin processing?Insulin contains 2 chains; A and B chain connected via sulfide bridges. Insulin prohormone contains a signal peptide directing it to the regulated secretory pathway. Insulin prohormone contains (from N- to C-terminus) the B, A and C chain. Disulfide bridges (through C-residues) keep the chains together.
What are the prohormone convertases (PCs) needed for insulin?
Where does PC1/3 cleave proinsulin?PC1/3 cleaves the B/C chain.
What happens when genes for PCs are deleted?Deletion of genes for PCs cause early diabetes and problems in the immune system.