ENZYMES, RECEPTORS, AND GENES

Acid α-glucosidase (acid maltase)

Deficiency in this enzyme causes Pompe Disease (Type II glycogen storage disease), which is associated with cardiomegaly.

α-L-iduronidase

Deficiency in this enzyme causes Hurler syndrome (MPS I-H), the most severe form of Mucopolysaccharidoses.

ATPases

Increased intracellular calcium activates this group of enzymes, which further hasten ATP depletion, propagating cell damage.

β-hexosaminidase

Deficiency in this enzyme leads to the inability to catabolize GM2 gangliosides, a characteristic of Tay-Sachs disease.

Branching enzyme

A lack of this enzyme can be associated with glycogen storage diseases.

Caspase-1 (IL-1 beta converting enzyme)

In pyroptosis, inflammasomes activate this caspase, which then cleaves the precursor of IL-1, converting it to an active form.

Caspases

These intrinsic enzymes are activated in apoptosis to degrade a cell's own DNA and proteins; they start as proenzymes/zymogens and are cleaved to become catalytically active.

Caspases 1, 4, and 5

These caspases induce cell death in pyroptosis.

Caspases 3 and 6

These are executioner caspases that activate DNases by cleaving their inhibitors and degrade structural components of the nuclear matrix during the execution phase of apoptosis.

Catalase

This enzyme scavenges and inactivates free radicals by converting hydrogen peroxide (H2O2) into oxygen (O2) and water (H2O).

Cytochrome oxidase

Cyanide inhibits this enzyme, thereby stopping oxidative phosphorylation and causing cell injury.

Cytochrome P450

This enzyme is found in the smooth endoplasmic reticulum of the liver and is responsible for converting exogenous chemicals or drugs into reactive toxic metabolites.

Debranching enzyme

Deficiency in this enzyme causes Type III glycogen storage disease, which is a hepatic form of glycogenosis.

DNases

Activated by executioner caspases during apoptosis by cleaving their inhibitors.

DNAses and RNAses

Chromatin dissolution, known as karyolysis, occurs due to the actions of these enzymes.

Endonucleases

Increased intracellular calcium activates this group of enzymes, leading to DNA and chromatin fragmentation.

Glucocerebrosidase

Deficiency of this enzyme, due to a mutation in its encoding gene, leads to the accumulation of glucocerebroside in phagocytes, characterizing Gaucher disease. Mutation of this gene is also the most common known genetic risk factor for Parkinson disease.

Glucose-6-phosphate dehydrogenase

Deficiency in this enzyme predisposes patients to episodic red cell hemolysis after infection or certain drug exposure.

Glucose-6-phosphatase

Deficiency in this enzyme causes Von Gierke disease (Type I glycogen storage disease), a hepatic form associated with glycogen storage in the liver and hypoglycemia.

Glutathione peroxidase

This enzyme scavenges and inactivates free radicals by converting hydrogen peroxide (H2O2) or hydroxyl radicals (̇OH) into water (H2O) with glutathione (GSH).

Lipases (Pancreatic lipases)

In acute pancreatitis, the release of activated forms of these enzymes into the substance of the pancreas and the peritoneal cavity leads to focal areas of fat destruction by liquefying the membranes of fat cells.

Liver phosphorylase

Deficiency in this enzyme causes Type VI glycogen storage disease, a hepatic form.

Lysosomal enzymes

These hydrolytic enzymes function in the acidic milieu of lysosomes to catalyze complex macromolecules; their leakage into the cytoplasm digests the cell in necrosis.

MLKL protein

In necroptosis, RIPK3 phosphorylates this protein, leading to plasma membrane degradation, leakage of contents, inflammation, and tissue damage.

Muscle phosphofructokinase

Deficiency in this enzyme causes Type VII glycogen storage disease, a myopathic form.

Muscle phosphorylase

Deficiency in this enzyme causes McArdle Disease (Type V glycogen storage disease), a myopathic form characterized by glycogen storage in muscles and impaired energy production.

Na+-K+ ATPase pump (Na+-K+ pump)

Failure of this energy-dependent ion pump in the plasma membrane leads to changes in ion concentrations and water influx, causing cellular swelling (hydropic changes).

NADPH oxidase

This plasma membrane multiprotein complex is found in activated neutrophils and macrophages and produces free radicals, which are used to destroy phagocytosed bacteria.

p53 protein

Derived from the TP53 gene, this protein keeps cells in the G1 phase to repair DNA damage or initiates apoptosis via the mitochondrial pathway if damage is too severe, thereby preventing cancer formation.

Phospholipases

Increased intracellular calcium activates this group of enzymes, which degrade phospholipids in the cell membrane, leading to membrane damage.

Proteases

Increased intracellular calcium activates this group of enzymes, which destroy proteins and can also lead to cytoskeletal abnormalities.

RIPK1 and RIPK3 (receptor-interacting protein kinases)

In necroptosis, ligation of TNFR1 recruits these kinases, with RIPK3 phosphorylating MLKL protein, leading to plasma membrane degradation.

RNAses

Activated by executioner caspases during apoptosis by cleaving their inhibitors.

Sphingomyelinase

Inherited deficiency of this enzyme leads to the lysosomal accumulation of sphingomyelin, which is characteristic of Niemann-Pick diseases Types A and B.

Superoxide dismutase

This enzyme scavenges and inactivates free radicals by converting superoxide anion (O2•) into hydrogen peroxide (H2O2).

Tyrosinase enzyme

This enzyme produces melanin by oxidizing tyrosine into dihydroxyphenylalanine.

Androgen receptor

The function of this receptor, located on the X chromosome, is mediated by testosterone and depends on the length of its CAG trinucleotide repeats, influencing sensitivity to androgen.

CFTR (Cystic fibrosis transmembrane conductance regulator)

Loss of this channel leads to defects in chloride transport, characteristic of Cystic Fibrosis.

Death receptors

These plasma membrane receptors, which include TNFR1 and Fas (CD95), initiate the extrinsic pathway of apoptosis upon engagement and contain a cytoplasmic "death domain" to deliver apoptotic signals.

Fas (CD95)

This is a type of death receptor found on many cell types that binds to Fas ligand (FasL) to initiate the extrinsic pathway of apoptosis.

Fas-associated death domain (FADD)

In the extrinsic pathway of apoptosis, this complex is formed when three or more Fas proteins come together, binding to caspase 8 (or caspase 10 in humans).

Fas ligand (FasL)

Found on cytotoxic T cells, this ligand binds to Fas (CD95) on target cells, initiating the extrinsic pathway of apoptosis.

G-protein coupled receptors

Downstream signaling of these receptors is the signaling pathway associated with pathologic hypertrophy.

Immune receptors

These receptors recognize microbial products in pyroptosis, leading to the activation of inflammasomes.

LDL receptor

Mutation in the gene encoding this receptor is the most common cause (80-85%) of familial hypercholesterolemia, resulting in inadequate removal of plasma LDL from the liver; it is involved in the transport and metabolism of cholesterol.

PI3K/AKT (phosphoinositide 3-kinase)

This is the signaling pathway for physiologic exercise-induced muscle hypertrophy.

TNFR1 (type 1 TNF receptor)

This is a type of death receptor that initiates extrinsic apoptosis; its ligation can also lead to necroptosis by recruiting RIPK1 and RIPK3.

FMR1 gene

Amplification of CGG trinucleotide repeats in this gene causes Fragile X syndrome, which when fully mutated (200-4000 repeats) leads to its transcriptional suppression and loss of function of its protein product, FMRP.

FMRP (protein product of FMR1 gene)

The loss of function of this widely expressed cytoplasmic protein, which normally binds mRNAs and regulates their intracellular transport to dendrites, is the molecular basis for intellectual disability and other somatic changes in Fragile X syndrome.

TP53 gene

This gene encodes a protein that plays a crucial role in preventing cancer by arresting cells in the G1 phase for DNA repair or initiating apoptosis if DNA damage is too severe.

p53 protein

Derived from the TP53 gene, this protein acts as a guardian of the genome by either halting the cell cycle in G1 for DNA repair or triggering apoptosis through the mitochondrial pathway if damage is irreparable, thus averting cancer development.

FBN-1 gene

An inherited defect in this gene, which encodes the extracellular glycoprotein Fibrillin-1, is the pathogenesis of Marfan syndrome, leading to loss of structural support in the extracellular matrix and excessive activation of TGF-β signaling.

LDL receptor gene

Mutation in this gene is the most common cause (80-85%) of familial hypercholesterolemia, resulting in the inadequate removal of plasma LDL by the liver due to dysfunctional or absent LDL receptors.

ApoB gene

Mutations in this gene can contribute to familial hypercholesterolemia by reducing the binding affinity of LDL molecules with LDL receptors.

PCSK9 gene

Activating mutations in this gene lead to a significant reduction in the number of LDL receptors on the cell surface due to increased degradation, contributing to familial hypercholesterolemia.

Glucocerebrosidase gene

Mutation in this gene causes a deficiency in the glucocerebrosidase enzyme, leading to the accumulation of glucocerebroside in phagocytes, which is characteristic of Gaucher disease. This mutation is also the most common known genetic risk factor for Parkinson disease.

MECP2 gene

Haploinsufficiency of this X-linked gene causes Rett syndrome, a condition characterized by progressive neurologic dysfunction and neurodevelopmental stagnation, as its protein product promotes heterochromatin formation.

NPC1 gene

Mutations in this gene are responsible for approximately 95% of Niemann-Pick Disease Type C cases, affecting the nonenzymatic transport of free cholesterol from lysosomes to the cytoplasm.

NPC2 gene

Mutations in this gene are implicated in Niemann-Pick Disease Type C, affecting the nonenzymatic transport of free cholesterol from lysosomes to the cytoplasm.

SRY (sex-determining region Y gene)

This gene is located on the Y chromosome and is solely responsible for determining male sex; its deletions are associated with azoospermia.

Androgen receptor gene

Located on the X chromosome, the function of this gene is mediated by testosterone and depends on the length of its CAG trinucleotide repeats, where shorter repeats increase sensitivity and longer repeats lead to hypogonadism.

SHOX (Short stature Homeobox) gene

Overexpression of this X-linked gene, due to uneven dosage compensation during X-inactivation in conditions like Klinefelter syndrome, contributes to tall stature and long legs.

BCL2 gene

When abnormal, this gene, part of the BCL2 family of proteins, is implicated in the development of B cell lymphomas.

CFTR gene (Cystic fibrosis transmembrane conductance regulator gene)

Loss of function of the channel encoded by this gene leads to defects in chloride transport, which is the defining characteristic of Cystic Fibrosis.

Hexosaminidase-beta subunit gene

Lack of the lysosomal enzyme encoded by this gene results in the inability to catabolize GM2 gangliosides, leading to their accumulation in neurons and causing Tay-Sachs disease.

α₁-antitrypsin gene

A genetic mutation affecting the gene responsible for encoding α₁-antitrypsin leads to defective intracellular transport and secretion, causing nonfunctional protein to accumulate in hepatocytes and inducing apoptosis, and also contributes to emphysema in the lungs.

FGFR2 gene

Mutations in this gene are associated with Apert syndrome, an autosomal dominant disorder that can sometimes arise from gonadal mosaicism in phenotypically normal parents.

HRAS gene

Mutations in this gene are associated with Costello syndrome, an autosomal dominant disorder that can sometimes arise from gonadal mosaicism in phenotypically normal parents.

PIK3CA/AKT/mTOR pathway genes

Mutations in genes within this signaling pathway are associated with various overgrowth syndromes, including Proteus Syndrome and CLOVES syndrome.

HLA-alleles

Polymorphisms in these genes are significant contributors to the hereditary component of complex multigenic disorders like Type 1 Diabetes Mellitus, often accounting for more than 50% of the risk.

The provided sources contain a total of 23 unique genes or gene-related concepts that fit your criteria, and the questions comprehensively cover the information available for each.