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Laminopathies
Laminopathies ('' lamino-'' + '' -pathy'') are a group of rare genetic disorders caused by mutations in genes encoding proteins of the nuclear lamina. Since the first reports of laminopathies in the late 1990s, increased research efforts have started to uncover the vital role of nuclear envelope proteins in cell and tissue integrity in animals. Laminopathies are a group of degenerative diseases, other disorders associated with inner nuclear membrane proteins are known as ''nuclear envelopathies''. Symptoms and signs Laminopathies and other nuclear envelopathies have a large variety of clinical symptoms including skeletal and/or cardiac muscular dystrophy, lipodystrophy and diabetes, dysplasia, dermo- or neuropathy, leukodystrophy, and progeria (premature aging). Most of these symptoms develop after birth, typically during childhood or adolescence. Some laminopathies however may lead to an early death, and mutations of lamin B1 ( LMNB1 gene) may be lethal before or at birth. Ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamin
Lamins, also known as nuclear lamins, are fibrous proteins in Intermediate filament#Type V – nuclear lamins, type V intermediate filaments, providing structural function and Transcription (biology), transcriptional regulation in the cell nucleus. Nuclear lamins interact with inner nuclear membrane proteins to form the nuclear lamina on the interior of the nuclear envelope. Lamins have elastic and mechanosensitive properties, and can alter Regulation of gene expression, gene regulation in a feedback response to mechanical cues. Lamins are present in all animals but are not found in microorganisms, plants or Fungus, fungi. Lamin proteins are involved in the disassembling and reforming of the nuclear envelope during mitosis, the positioning of nuclear pores, and programmed cell death. Mutations in lamin genes can result in several Genetic disorder, genetic Laminopathy, laminopathies, which may be life-threatening. History Lamins were first identified in the cell nucleus, using E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LMNA
Prelamin-A/C, or lamin A/C is a protein that in humans is encoded by the ''LMNA'' gene. Lamin A/C belongs to the lamin family of proteins. Function In the setting of ZMPSTE24 deficiency, the final step of lamin processing does not occur, resulting in an accumulation of farnesyl-prelamin A. In Hutchinson–Gilford progeria syndrome, a 50-amino acid deletion in prelamin A (amino acids 607–656) removes the site for the second endoproteolytic cleavage. Consequently, no mature lamin A is formed, and a farnesylated mutant prelamin A (progerin) accumulates in cells. The nuclear lamina consist of a two-dimensional matrix of proteins located next to the inner nuclear membrane. The lamin family of proteins make up the matrix and are highly conserved in evolution. During mitosis, the lamina matrix is reversibly disassembled as the lamin proteins are phosphorylated. Lamin proteins are thought to be involved in nuclear stability, chromatin structure and gene expression. Vertebrate l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hutchinson–Gilford Progeria Syndrome
Progeria is a specific type of progeroid syndrome, also known as Hutchinson–Gilford syndrome or Hutchinson–Gilford progeroid syndrome (HGPS). A single gene mutation is responsible for causing progeria. The affected gene, known as lamin A (''LMNA''), makes a protein necessary for holding the cell nucleus together. When this gene mutates, an abnormal form of lamin A protein called progerin is produced. Progeroid syndromes are a group of diseases that cause individuals to age faster than usual, leading to them appearing older than they actually are. People born with progeria typically live until their mid- to late-teens or early twenties. Severe cardiovascular complications usually develop by puberty, later on resulting in death. Signs and symptoms Most children with progeria appear normal at birth and during early infancy. Children with progeria usually develop the first symptoms during their first few months of life. The earliest symptoms may include a failure to thrive and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nuclear Lamina
The nuclear lamina is a dense (~30 to 100 nm thick) fibrillar network inside the nucleus of eukaryote cells. It is composed of intermediate filaments and membrane associated proteins. Besides providing mechanical support, the nuclear lamina regulates important cellular events such as DNA replication and cell division. Additionally, it participates in chromatin organization and it anchors the nuclear pore complexes embedded in the nuclear envelope. The nuclear lamina is associated with the inner face of the inner nuclear membrane of the nuclear envelope, whereas the outer face of the outer nuclear membrane is continuous with the endoplasmic reticulum. The nuclear lamina is similar in structure to the nuclear matrix, that extends throughout the nucleoplasm. Structure and composition The nuclear lamina consists of two components, lamins and nuclear lamin-associated membrane proteins. The lamins are type V intermediate filaments which can be categorized as either A-type ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Progeria
Progeria is a specific type of progeroid syndrome, also known as Hutchinson–Gilford syndrome or Hutchinson–Gilford progeroid syndrome (HGPS). A single gene mutation is responsible for causing progeria. The affected gene, known as lamin A (''LMNA''), makes a protein necessary for holding the cell nucleus together. When this gene mutates, an abnormal form of lamin A protein called progerin is produced. Progeroid syndromes are a group of diseases that cause individuals to age faster than usual, leading to them appearing older than they actually are. People born with progeria typically live until their mid- to late-teens or early twenties. Severe cardiovascular complications usually develop by puberty, later on resulting in death. Signs and symptoms Most children with progeria appear normal at birth and during early infancy. Children with progeria usually develop the first symptoms during their first few months of life. The earliest symptoms may include a failure to thrive an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inner Nuclear Membrane Protein
Inner nuclear membrane proteins (INM proteins) are membrane proteins that are embedded in or associated with the Inner nuclear membrane, inner membrane of the nuclear envelope. There are about 60 INM proteins, most of which are poorly characterized with respect to structure and function. Among the few well-characterized INM proteins are lamin B receptor (LBR), TOR1AIP1, lamina-associated polypeptide 1 (LAP1), thymopoietin, lamina-associated polypeptide-2 (LAP2), emerin and LEM domain-containing protein 3, MAN1. Common structural features Several integral nuclear membrane proteins of different size and structure have been identified. It is proposed that they share some structural features with respect to nucleoplasmic Protein domain, domain(s) and lipid-soluble domain(s). Some INM proteins contain common protein domain structures, and can thus be categorised into known Protein family#Protein domains and motifs, protein domain families. These include the LEM domain, LEM-, SUN domai ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamin B2
Lamin B2 is a protein that in humans is encoded by the ''LMNB2'' gene. It is the second of two type B nuclear lamins, and it is associated with laminopathies. See also * Lamin B receptor Lamin-B receptor is a protein, and in humans, it is encoded by the ''LBR'' gene. Function The protein encoded by this gene belongs to the ERG4/ ERG24 family. It localizes to the inner membrane of the nuclear envelope and anchors the lamina a ... * Barraquer–Simons syndrome * Pelger–Huët anomaly External links * References Genes mutated in mice {{biochemistry-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiac Arrhythmias
Arrhythmias, also known as cardiac arrhythmias, are irregularities in the heartbeat, including when it is too fast or too slow. Essentially, this is anything but normal sinus rhythm. A resting heart rate that is too fast – above 100 beats per minute in adults – is called tachycardia, and a resting heart rate that is too slow – below 60 beats per minute – is called bradycardia. Some types of arrhythmias have no symptoms. Symptoms, when present, may include palpitations or feeling a pause between heartbeats. In more serious cases, there may be lightheadedness, passing out, shortness of breath, chest pain, or decreased level of consciousness. While most cases of arrhythmia are not serious, some predispose a person to complications such as stroke or heart failure. Others may result in sudden death. Arrhythmias are often categorized into four groups: extra beats, supraventricular tachycardias, ventricular arrhythmias and bradyarrhythmias. Extra beats include ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diabetes Mellitus
Diabetes mellitus, commonly known as diabetes, is a group of common endocrine diseases characterized by sustained hyperglycemia, high blood sugar levels. Diabetes is due to either the pancreas not producing enough of the hormone insulin, or the cells of the body becoming unresponsive to insulin's effects. Classic symptoms include polydipsia (excessive thirst), polyuria (excessive urination), polyphagia (excessive hunger), Weight loss#Unintentional, weight loss, and blurred vision. If left untreated, the disease can lead to various health complications, including disorders of the Cardiovascular disease, cardiovascular system, Diabetic retinopathy, eye, Diabetic nephropathy, kidney, and Diabetic neuropathy, nerves. Diabetes accounts for approximately 4.2 million deaths every year, with an estimated 1.5 million caused by either untreated or poorly treated diabetes. The major types of diabetes are Type 1 diabetes, type 1 and Type 2 diabetes, type 2. The most common treatment for ty ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muscle Weakness
Muscle weakness is a lack of muscle strength. Its causes are many and can be divided into conditions that have either true or perceived muscle weakness. True muscle weakness is a primary symptom of a variety of skeletal muscle diseases, including muscular dystrophy and inflammatory myopathy. It occurs in neuromuscular junction disorders, such as myasthenia gravis. Muscle weakness can also be caused by low levels of potassium and other electrolytes within muscle cells. It can be temporary or long-lasting (from seconds or minutes to months or years). The term myasthenia is from my- from Greek μυο meaning "muscle" + -asthenia ἀσθένεια meaning " weakness". Types Neuromuscular fatigue can be classified as either "central" or "peripheral" depending on its cause. Central muscle fatigue manifests as an overall sense of energy deprivation, while peripheral muscle fatigue manifests as a local, muscle-specific inability to do work. Neuromuscular fatigue Nerves control the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shortness Of Breath
Shortness of breath (SOB), known as dyspnea (in AmE) or dyspnoea (in BrE), is an uncomfortable feeling of not being able to breathe well enough. The American Thoracic Society defines it as "a subjective experience of breathing discomfort that consists of qualitatively distinct sensations that vary in intensity", and recommends evaluating dyspnea by assessing the intensity of its distinct sensations, the degree of distress and discomfort involved, and its burden or impact on the patient's activities of daily living. Distinct sensations include effort/work to breathe, chest tightness or pain, and "air hunger" (the feeling of not enough oxygen). The tripod position is often assumed to be a sign. Dyspnea is a normal symptom of heavy physical exertion but becomes disease, pathological if it occurs in unexpected situations, when resting or during light exertion. In 85% of cases it is due to asthma, pneumonia, cardiac ischemia, reflux/LPR, cardiac ischemia, COVID-19, interstitial lung di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LMNB1
Lamin-B1 is a protein that in humans is encoded by the ''LMNB1'' gene. The nuclear lamina consists of a two-dimensional matrix of proteins located next to the inner nuclear membrane. The lamin family of proteins make up the matrix and are highly conserved in evolution. During mitosis, the lamina matrix is reversibly disassembled as the lamin proteins are phosphorylated. Lamin proteins are thought to be involved in nuclear stability, chromatin structure, and gene expression. Vertebrate lamins consist of two types, A and B. This gene encodes one of the two B type proteins, B1. Lamin B, along with heterochromatin, is anchored to the inner surface of the nuclear membrane by the lamin B receptor. Interactions LMNB1 has been shown to interact with Thymopoietin. When double-strand breaks are induced in DNA by ionizing radiation, lamin B1 promotes repair of the breaks, as well as cell survival, by maintaining the level of the RAD51 protein that is employed in homologous recombination ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
