Disorders week 1 Flashcards
progeria
- type of mutation
- protein involved
- effect
- prognosis
- first success of the human genome project
- point mutation causing and unusable form of lamin A
- nuclear lamin cannot be formed properly
- age quickly and only live into their teens
restrictive dermopathy
- genetic inheritance
- gene involved
- effect
- autosomal recessive
- loss of a gene that is responsible for the cleavage of pre-lamin into mature nuclear lamin
- skin does not grow and the child suffocates in own skin
Huntington’s disease
- effect of genetic change
- genetic change to the gene
- significance in cell bio
- determinant of severity
- determinant of age of onset
- brain cell nuclei show a high level of the protein huntingtin, which is typically found in the cytoplasm
- the accumulation of this protein disturbs nuclear function
- defect in gene is caused by an accumulation of an unnatural amount of trinucleotide repeats
- Relevance in cell bio is that this protein got into an area of the cell that its not supposed to via a mechanism probably having to do with the conformation of the protein (trinucleotide repeat is not an NLS)
- severity of the disease is correlated with how much huntingtin protein is found in the nuclei
- age of onset is correlated with the number of trinucleotide repeats
Cancer and exportin 1
- exprotin 1 is responsible to removing tumor suppressing proteins from the nucleus so the cell is able to divide
- in some cancerous cells, exporting 1 expression is increased, causing there to be a greater removal of tumor suppressing TF’s etc.
- several small molecule inhibitors of this protein have been developed and are now in stage 2 clinical trials
Tay-Sachs
- classification
- gene involved
- effect
- build up of what
- symptoms
- Lysosomal storage disease
- deficiency in hexosaminidase A
- disrupts sphingolipid breakdown
- results in the buildup of GM2 ganglioside
- causes mental retardation, blindness, and early death
Fabry’s
- classification
- gene involved
- build up of what
- symptoms
- treatment
- lysosomal storage disease
- alpha galactosidase A deficiency
- results in build up of ceramide in lysosomes
- rash on the inner lip/tongue and kidney failure
- treated with enzyme replacement therapy
Gaucher’s disease
- classification
- treatment
- lysosomal storage disesae
- also treated with enzyme replacement therapy
niemann-pick
-classification
lysosomal storage disease
GM1 gangliosidosis
-calssification
-lysosomal storage disease
Asthma/Anaphylaxis
- molecules which cause symptoms
- classification of this molecule
- are induced by leukotrienes which cause vasodilation and bronchoconstriction in asthma/anaphylaxis
- a membrane lipid called and eicosanoid
mycoplasma (walking) pneumonia
- prevalence
- cause
- cellular pathology
- symptoms
- perpetuation
- most common form of pneumonia
- caused by an increase in the fluidity of ciliated cells in the lungs
- mycoplasma burrows down to the root of the cilia where is feeds on the cholesterol of the plasma membrane
- causes the cilia not to beat properly
- results in mucus accumulation in the respiratory tract, creating a favorable environment for the mycoplasma
HIV
- mechanism of infection
- cellular consequences of infection with regards to membranes
- class significance
- takes advantage of the fusogenic nature of plasma membranes
- HIV has a viral glycoprotein that is recognized by the CD4 receptor on T cells, macrophages, and other cell types
- when HIV binds, there is rapid fusion of the membrane, spilling HIV nucleic acid into the cell and the viral membrane is incorporated in the cells
- incorporation of the membrane allows infected cells to fuse with other CD4+ cells, resulting multinucleated cells are incapable of carrying out their immune function
- glycoproteins allow for entry and those glycoproteins then allow other cells to fuse, demonstrating the fusogenic property of cell membranes
Measles
- mode of action
- similar to
- propogation
- class significance
- takes advantage of fusogenic properties of phospholipids
- same as HIV
- infected cells can fuse with healthy cells, propagating the virus
- fusion of cell membranes
Toxoplasmosis
- class of organism
- found where
- mode of action
- class significance
- protozoan found in cat feces
- causes severe birth defects in unborn children
- binds to certain cells in the body based on the glycoproteins of those cells
- shows a clinical significance of glycoproteins
Coccidiosis
- classification of organism
- found where
- mode of action
- class significance
- protozoan that can live in the water and food source of developing countries
- binds to glycoproteins of cells in the GI tract
- the composition of glycoproteins on the cell surface changes as you move down the GI and different strains of this protist latch on to different areas
- you can tell which type of coccidiosis it is by where the pain is and in turn this can help public health professionals identify the problem
- another example of clinical glycoprotein problems
Cystic Fibrosis
- cause, gene involved
- classification of gene product
- mechanism
- cell bio sig
- caused by a mutation in the CFTR protein, which is an ABC ATPase
- without this protein being functional, Cl- transport across the membrane can not be regulated.
- cell biology: defects in an ABD ATPase
Tangier disease -cause and protein involved -mechanism -prognosis -research of this disease has led to -
- Caused by a defect in ATP Binding cassette 1, another ABC ATPase
- can not shuttle cholesterol out of the cell due to a defect in this transporter
- without cholesterol to pick up, HDL is quickly cleared from the plasma causing an HDL deficiency and a build up of cholesterol in the vessel wall
- results in premature coronary heat disease CHD
- usually die in 40s or 50s due to CHD
- study of this disease have identified mechanisms of reverse cholesterol transport and the roles of HDL and LDL in the body
- this is a disorder caused by a defective ABC ATPase, ATP binding cassette 1
P glycoprotein/MDR complex in cancer
- These are the same thing and is are an ABC ATPase that is capable of pumping out toxins
- to treat cancer we often use toxic drugs, however there is a problem when this protein is overexpressed in cancer cells and the cells are capable of shuttling out all of the drug so it can not take effect
- another ABC ATPase disorder
familial hypercholesterolemia
- due to
- genetic inheritance
- homozygote symptom
- 3 defects found to cause this
- these problems all lead to
- class significance
- due to defective receptor mediated endocytosis
- autosomal dominant disease
- homozygotes have extremely elevated cholesterol and die of cardio problems before 30’s
- seferal defects found: failure of LDL to bind properly to the receptor,failure of receptor to clutter into coated pits, mutant receptor that missing the membrane spanning segment causing abnormal binding and eventual secretion
- all of these problems result in increased blood cholesterol and lead to arteriosclerosis
- defective endocytosis
rabies, influenza
- mode of entry
- cell bio significance
- both use receptor mediated endocytosis to enter the cell
- endocytosis gone wrong
streptococcus
- second most common bacterial pathogen in humans
- has a carb coat on cell surface which macrophages do not recognize and therefor can not phagocytose
legionnaires disease
- organism that causes it
- mechanism of action
- cell bio sig
- L. pneumophila, a bacterium, is the cause
- it is phagocytes by the epithelial cells of the respiratory tract
- once inside the phagosome, it quickly neutralizes the environment so the phagosome can not fuse with the lysosome to form thee phagolysosome
- then proliferates
- this is an example of a phagocytosis problem
Leishmania and leprosy
- orgnisms that cause each
- mechanism of action
- cell bio sig
- protozoan causes leish and mycobacterium causes pep
- these organisms thrive in the acidic environment of the phagolysosome and multiply
- these utilize phagocytosis to their advantage
I cell disease
- cause
- protein affected
- mechanism
- cell bio sig
- accumulation of a variety of polymers in the lysosome and highly elevated secretion of lysosomal enzymes
- this is caused by a dysfunctional N-acetylglucosamine phosphotransferase, which is responsible for making the phsopho-mannose that acts as a signal for enzymes to target the lysosome
- studying this lead to the discovery of the lysosomal protein targeting system
- since there is no signal, the proteins are excreted by default and the lysosomes are free of enzymes
- this is a problem with protein targeting
mucopolysaccharidoses 1-4
- most common of the LSD’s
- lysosomes become engorged with mucopolysaccharides (glycosaminoglycans)
zellwegger syndrome and neonatal adrenoleukodystrophy (NALD)
- these two diseases are due to mutations in the SKL signal that sends proteins to the peroxisomes
- this results in the proteins destined for the peroxisomes never make it there and the peroxisomes do not function properly
Infantile hypoglycemia
-also caused by an ABC-type ATPase