ALMS1
Encyclopedia
Alstrom syndrome 1 also known as ALMS1 is a protein
which in humans is encoded by the ALMS1 gene
.
The gene is expressed in fetal tissues including the aorta
, brain
, eye
, kidney
, liver
, lung
, olfactory bulb
, pancreas
, skeletal muscle
, spleen
and testis. The protein is found in the cytoplasm
, centrosome
, cell projections and cilium basal body
. During mitosis
it localizes to both spindle poles.
of Alms1 by short interfering RNA in mouse inner medullary collecting duct cells caused defective ciliogenesis. Cilia were stunted and treated cells lacked the ability to increase calcium influx in response to mechanical stimuli.
with a total of 81 disease-causing mutation
s.
Multiple mutations are known: the current (2007) total is 79. These include both nonsense and frameshift mutations. Most of the mutations have been found in exon
s 8,10 and 16.
in Bar Harbor, Maine
, USA with the University of Southampton
, UK isolated ALMS1 as the single gene responsible for Alström syndrome
.
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
which in humans is encoded by the ALMS1 gene
Gene
A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...
.
Molecular biology
The gene is located on the short arm of chromosome 2 (2p13.2) on the plus (Watson) strand. It is 224,161 bases in length organised into 23 exons. The encoded protein has 4,167 amino acids and molecular weight of 460,937 Da. Three isofoms are known. The protein itself has a large tandem-repeat domain comprising 34 imperfect repetitions of 47 amino acids.The gene is expressed in fetal tissues including the aorta
Aorta
The aorta is the largest artery in the body, originating from the left ventricle of the heart and extending down to the abdomen, where it branches off into two smaller arteries...
, brain
Human brain
The human brain has the same general structure as the brains of other mammals, but is over three times larger than the brain of a typical mammal with an equivalent body size. Estimates for the number of neurons in the human brain range from 80 to 120 billion...
, eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
, kidney
Kidney
The kidneys, organs with several functions, serve essential regulatory roles in most animals, including vertebrates and some invertebrates. They are essential in the urinary system and also serve homeostatic functions such as the regulation of electrolytes, maintenance of acid–base balance, and...
, liver
Liver
The liver is a vital organ present in vertebrates and some other animals. It has a wide range of functions, including detoxification, protein synthesis, and production of biochemicals necessary for digestion...
, lung
Human lung
The human lungs are the organs of respiration in humans. Humans have two lungs, with the left being divided into two lobes and the right into three lobes. Together, the lungs contain approximately of airways and 300 to 500 million alveoli, having a total surface area of about in...
, olfactory bulb
Olfactory bulb
The olfactory bulb is a structure of the vertebrate forebrain involved in olfaction, the perception of odors.-Anatomy:In most vertebrates, the olfactory bulb is the most rostral part of the brain. In humans, however, the olfactory bulb is on the inferior side of the brain...
, pancreas
Pancreas
The pancreas is a gland organ in the digestive and endocrine system of vertebrates. It is both an endocrine gland producing several important hormones, including insulin, glucagon, and somatostatin, as well as a digestive organ, secreting pancreatic juice containing digestive enzymes that assist...
, skeletal muscle
Skeletal muscle
Skeletal muscle is a form of striated muscle tissue existing under control of the somatic nervous system- i.e. it is voluntarily controlled. It is one of three major muscle types, the others being cardiac and smooth muscle...
, spleen
Spleen
The spleen is an organ found in virtually all vertebrate animals with important roles in regard to red blood cells and the immune system. In humans, it is located in the left upper quadrant of the abdomen. It removes old red blood cells and holds a reserve of blood in case of hemorrhagic shock...
and testis. The protein is found in the cytoplasm
Cytoplasm
The cytoplasm is a small gel-like substance residing between the cell membrane holding all the cell's internal sub-structures , except for the nucleus. All the contents of the cells of prokaryote organisms are contained within the cytoplasm...
, centrosome
Centrosome
In cell biology, the centrosome is an organelle that serves as the main microtubule organizing center of the animal cell as well as a regulator of cell-cycle progression. It was discovered by Edouard Van Beneden in 1883...
, cell projections and cilium basal body
Basal body
A basal body is an organelle formed from a centriole, and a short cylindrical array of microtubules. It is found at the base of a eukaryotic undulipodium and serves as a nucleation site for the growth of the axoneme microtubules...
. During mitosis
Mitosis
Mitosis is the process by which a eukaryotic cell separates the chromosomes in its cell nucleus into two identical sets, in two separate nuclei. It is generally followed immediately by cytokinesis, which divides the nuclei, cytoplasm, organelles and cell membrane into two cells containing roughly...
it localizes to both spindle poles.
Function
KnockdownGene knockdown
Gene knockdown refers to techniques by which the expression of one or more of an organism's genes is reduced, either through genetic modification or by treatment with a reagent such as a short DNA or RNA oligonucleotide with a sequence complementary to either an mRNA transcript or a gene...
of Alms1 by short interfering RNA in mouse inner medullary collecting duct cells caused defective ciliogenesis. Cilia were stunted and treated cells lacked the ability to increase calcium influx in response to mechanical stimuli.
Disease association
Mutations in the ALMS1 gene have been found to be causative for Alström syndromeAlstrom syndrome
Alström syndrome is a rare genetic disorder caused by mutations in the gene ALMS1. It is among the rarest genetic disorders in the world, as currently it has only 266 reported cases in medical literature and over 501 known cases in 47 countries. It was first described by Carl-Henry Alström in...
with a total of 81 disease-causing mutation
Mutation
In molecular biology and genetics, mutations are changes in a genomic sequence: the DNA sequence of a cell's genome or the DNA or RNA sequence of a virus. They can be defined as sudden and spontaneous changes in the cell. Mutations are caused by radiation, viruses, transposons and mutagenic...
s.
Multiple mutations are known: the current (2007) total is 79. These include both nonsense and frameshift mutations. Most of the mutations have been found in exon
Exon
An exon is a nucleic acid sequence that is represented in the mature form of an RNA molecule either after portions of a precursor RNA have been removed by cis-splicing or when two or more precursor RNA molecules have been ligated by trans-splicing. The mature RNA molecule can be a messenger RNA...
s 8,10 and 16.
Discovery
The Jackson LaboratoryJackson Laboratory
The Jackson Laboratory was founded in Bar Harbor, Maine in 1929 by former University of Maine and University of Michigan president C. C. Little under the name Roscoe B...
in Bar Harbor, Maine
Maine
Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...
, USA with the University of Southampton
University of Southampton
The University of Southampton is a British public university located in the city of Southampton, England, a member of the Russell Group. The origins of the university can be dated back to the founding of the Hartley Institution in 1862 by Henry Robertson Hartley. In 1902, the Institution developed...
, UK isolated ALMS1 as the single gene responsible for Alström syndrome
Alstrom syndrome
Alström syndrome is a rare genetic disorder caused by mutations in the gene ALMS1. It is among the rarest genetic disorders in the world, as currently it has only 266 reported cases in medical literature and over 501 known cases in 47 countries. It was first described by Carl-Henry Alström in...
.