Transcript
Cellular GeneticsCellular Genetics
Fall 2006Fall 2006
Synthesis of Proteins and Synthesis of Proteins and the ERthe ER
Lysosomal Lysosomal enzymesenzymes
Membrane Membrane proteinsproteins
Secretory Secretory proteins proteins
Proteins are Proteins are polypeptides polypeptides
MacromoleculeMacromolecules composed of s composed of amino acids amino acids joined by joined by peptide bondspeptide bonds
Proteins have levels of Proteins have levels of structurestructure
The structure of The structure of protein protein molecules is molecules is dependent upon dependent upon the sequence of the sequence of the amino acidsthe amino acids
It is also It is also dependent upon dependent upon the the intermolecular intermolecular forces between forces between the amino acidsthe amino acids
ChaperonesChaperones
Chaperones are Chaperones are molecules that molecules that assist proteins assist proteins in the process in the process of attaining of attaining their final their final structurestructure
MutationsMutations
Mutations in the sequence of Mutations in the sequence of amino acids can result in amino acids can result in misfoldingmisfolding
Misfolding results in an Misfolding results in an abnormal shapeabnormal shape
Misfolded proteins are regarded Misfolded proteins are regarded as defective and are removed as defective and are removed by the ER and degradedby the ER and degraded
Misfolded proteins that are not Misfolded proteins that are not removed cause diseaseremoved cause disease
Proteins affectedProteins affected
Membrane channels( Cystic Membrane channels( Cystic fibrosis, Cl-1 channel)fibrosis, Cl-1 channel)
Receptors located on the Receptors located on the outside of membranes( FH – outside of membranes( FH – LDL receptor in LDL receptor in hypercholesterolemia)hypercholesterolemia)
Enzymes( Enzyme deficiency – Enzymes( Enzyme deficiency – lactase deficiency)lactase deficiency)
Enzyme and substrateEnzyme and substrate
Enzymes Enzymes dependent dependent upon the shape upon the shape of the active of the active site to bind the site to bind the substratesubstrate
( reactants)( reactants) No product will No product will
be formed be formed without the without the association of association of the Enzyme the Enzyme and substrateand substrate
Lactose intoleranceLactose intolerance
Lactose IntoleranceLactose Intolerance
Lactose intoleranceLactose intolerance
How prevalent is How prevalent is Lactose Lactose Intolerance? Intolerance?
About 70% of the About 70% of the world's population world's population just can't drink milk just can't drink milk or eat dairy or eat dairy products without products without getting an upset getting an upset stomach. stomach.
Lactose Intolerance Lactose Intolerance is a recessive is a recessive genetic disorder genetic disorder and happens most and happens most often in people of often in people of African, Asian and African, Asian and Mediterranean Mediterranean descent. descent.
SymptomsSymptoms
It is caused by a deficiency of It is caused by a deficiency of lactase, an enzyme needed to lactase, an enzyme needed to absorb and digest lactose absorb and digest lactose (milk sugar). (milk sugar).
Undigested lactose lingers in Undigested lactose lingers in the intestine. the intestine.
Fermentation occurs - creating Fermentation occurs - creating intestinal discomfort intestinal discomfort (abdominal pain, bloating, gas (abdominal pain, bloating, gas and diarrhea). and diarrhea).
Lactase enzymeLactase enzyme
LactaseLactase
The enzyme The enzyme lactase will lactase will break down break down lactose into lactose into glucose and glucose and galactosegalactose
ReactionReaction
Cystic fibrosisCystic fibrosis
Chloride Chloride channel in the channel in the plasma plasma membranemembrane
Affects the Affects the lining of the lining of the respiratory treerespiratory tree
CFTR – CFTR –
Cystic fibrosisCystic fibrosis
transconductance transconductance regulatorregulator
ABC transporterABC transporter
Requires ATPRequires ATP Moves chloride Moves chloride
across the across the membranes in membranes in the lungthe lung
LysosomesLysosomes
Used in Used in recyclingrecycling
Digestion of Digestion of complex complex molecules to molecules to form simpler form simpler moleculesmolecules
Secretory Secretory productsproducts
Developmental Developmental processesprocesses
Structure forms Structure forms from the Rough from the Rough endoplasmic endoplasmic reticulumreticulum
Acid interiorAcid interior CompartmentalCompartmental
ized so that it ized so that it does not does not rupturerupture
At least 40 At least 40 enzymes that enzymes that can be found in can be found in lysosomeslysosomes
Lysosomal Storage Lysosomal Storage DiseaseDisease
Fabry DiseaseFabry Disease
FabryFabry
Fabry disease is a Fabry disease is a lysosomal storage lysosomal storage disorder seen in disorder seen in one out of every one out of every 40,000 people. It 40,000 people. It is caused by a is caused by a deficiency in the deficiency in the enzyme alpha-enzyme alpha-galactosidase galactosidase which then results which then results in the body’s in the body’s inability to break inability to break down specific down specific fatty substances fatty substances called called globotriaosylceraglobotriaosylceramide (abbreviated mide (abbreviated GL-3 or Gb3). GL-3 or Gb3).
Hurler- SchieHurler- Schie
MucopolysaccharidosiMucopolysaccharidosis I is a lysosomal s I is a lysosomal storage disorder that storage disorder that is abbreviated MPS I is abbreviated MPS I and sometimes called and sometimes called Hurler syndrome, Hurler syndrome, Hurler-Scheie Hurler-Scheie syndrome, or Scheie syndrome, or Scheie syndrome. It is syndrome. It is caused by a caused by a deficiency in the deficiency in the enzyme alpha-enzyme alpha-iduronidase which is iduronidase which is needed to break needed to break down certain complex down certain complex sugars called sugars called glycosaminoglycans glycosaminoglycans (abbreviated GAGs (abbreviated GAGs and formerly called and formerly called mucopolysaccharides)mucopolysaccharides). .
MucolipidosisMucolipidosis
Lysosomal Lysosomal storage diseasestorage disease
Enzyme lackingEnzyme lacking MP3MP3 New treatmentNew treatment
Pamidronate Pamidronate Test with urine Test with urine
spot testspot test
PeroxisomesPeroxisomes
PeroxisomesPeroxisomes are are ubiquitous ubiquitous organellesorganelles in in eukaryoteseukaryotes that that function to rid the function to rid the cellcell of toxic substances. of toxic substances. They have a single They have a single membranemembrane that that separates their separates their contents from the contents from the cytosolcytosol (the internal (the internal fluid of the cell) and fluid of the cell) and that contains that contains membrane proteins membrane proteins critical for various critical for various functions, such as functions, such as importing proteins importing proteins into the organelles into the organelles
AdrenoleukodystrophyAdrenoleukodystrophy
Rare genetic diseaseRare genetic disease Neuromuscular degenerationNeuromuscular degeneration Demyelination of neuronsDemyelination of neurons Muscular atrophyMuscular atrophy Loss of hearing and speechLoss of hearing and speech
AdrenoleukodystrophyAdrenoleukodystrophy
Recent evidence suggests that Recent evidence suggests that a mixture of oleic acid and a mixture of oleic acid and euric acid, known as euric acid, known as "Lorenzo's Oil," administered "Lorenzo's Oil," administered to boys with X-ALD can reduce to boys with X-ALD can reduce or delay the appearance of or delay the appearance of symptoms. symptoms.
X-AldX-Ald
People with ALD accumulate People with ALD accumulate high levels of saturated, very high levels of saturated, very long chain fatty acids (VLCFA) long chain fatty acids (VLCFA) in the brain and adrenal cortex in the brain and adrenal cortex because they do not produce because they do not produce the enzyme that breaks down the enzyme that breaks down these fatty acids in the normal these fatty acids in the normal manner manner
Gene Location on XGene Location on X
ALD - TreatmentALD - Treatment
OilOil Adrenal Adrenal
hormoneshormones Bone Marrow Bone Marrow
transplanttransplant Stem Cell Stem Cell
transplanttransplant
Lorenzo’s OilLorenzo’s Oil
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