ALMS1

ALMS1
Identifiers
AliasesALMS1, ALSS, centrosome and basal body associated protein, ALMS1 centrosome and basal body associated protein
External IDsOMIM: 606844; MGI: 1934606; HomoloGene: 49406; GeneCards: ALMS1; OMA:ALMS1 - orthologs
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_015120
NM_001378454

NM_145223

RefSeq (protein)

NP_055935

NP_660258

Location (UCSC)Chr 2: 73.39 – 73.63 MbChr 6: 85.56 – 85.68 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

Alstrom syndrome 1 also known as ALMS1 is a protein which in humans is encoded by the ALMS1 gene.[5][6]

Gene

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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 isoforms are known. Mutations associated with disease are usually found in exons 8, 10 and 16.

Tissue and subcellular distribution

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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.

Structure

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The protein has a large tandem-repeat domain comprising 34 imperfect repetitions of 47 amino acids as well as additional low complexity regions.

Function

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The encoded protein functions in microtubule organization, particularly in the formation and maintenance of cilia. Mutations in this gene cause Alstrom syndrome. There is a pseudogene for this gene located adjacent in the same region of chromosome 2. Alternative splice variants have been described but their full length nature has not been determined. [provided by RefSeq, Apr 2014].

Disease association

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Mutations in the ALMS1 gene have been found to be causative for Alström syndrome with a total of 81 disease-causing mutations.[7]

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 exons 8,10 and 16.

Knockdown 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.[8]

Organ systems

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Primary cilia are hair-like projections that are on the surface of many cell types. ALMS1 is localized to the basal body of cilia and will help regulate signaling pathways all over the body. When there is a mutation in the ALMS1, the primary cilia will become dysfunctional. This will affect many pathways in the body due to this mutation. The Endocrine system is affected by a mutation in ALMS1 by having symptoms of early-onset obesity, insulin resistance, and type 2 diabetes.[9] When looking at the cardiovascular system there is a symptom of dilated cardiomyopathy, which can lead to heart failure. In the sensory system, there is a disease called cone-rod dystrophy that takes place because of ALMS1 which can cause loss of hearing and vision. With the renal system, the mutation can cause progressive kidney dysfunction which can lead to end-stage renal disease. Lastly, the hepatic system can be affected by fatty liver disease.[10] The mutation will cause different kinds of reactions in the organ systems.

Kidney damage

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ALMS1 has a very critical role in maintaining renal function and blood pressure homeostasis. It is hypothesized that a mutation in ALMS1 in macula densa cells will amplify tubuloglomerular feedback (TGF) and cause some problems in the kidneys due to an overreaction to sodium changes.[11] The TGF mechanism will then reduce the glomerular filtration rate (GFR). This can lead to hypertension and progressive kidney damage. All tests were done on ALMS1 knockout rats, and the outcome was higher glomerular capillary pressure and increased arterial blood pressure. Blood flow dynamics were also affected by these changes.

Discovery

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The Jackson Laboratory in Bar Harbor, Maine, USA with the University of Southampton, UK identified ALMS1 as the single gene responsible for Alström syndrome.[5][12]

References

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  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000116127Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000063810Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ a b Collin GB, Marshall JD, Cardon LR, Nishina PM (February 1997). "Homozygosity mapping of Alström syndrome to chromosome 2p". Human Molecular Genetics. 6 (2): 213–219. doi:10.1093/hmg/6.2.213. PMID 9063741.
  6. ^ Nagase T, Ishikawa K, Nakajima D, Ohira M, Seki N, Miyajima N, et al. (April 1997). "Prediction of the coding sequences of unidentified human genes. VII. The complete sequences of 100 new cDNA clones from brain which can code for large proteins in vitro". DNA Research : an International Journal for Rapid Publication of Reports on Genes and Genomes. 4 (2): 141–150. doi:10.1093/dnares/4.2.141. PMID 9205841.
  7. ^ Joy T, Cao H, Black G, Malik R, Charlton-Menys V, Hegele RA, et al. (Dec 2007). "Alstrom syndrome (OMIM 203800): a case report and literature review". Orphanet Journal of Rare Diseases. 2 (1): 49. doi:10.1186/1750-1172-2-49. PMC 2266715. PMID 18154657.
  8. ^ Li G, Vega R, Nelms K, Gekakis N, Goodnow C, McNamara P, et al. (January 2007). "A role for Alström syndrome protein, alms1, in kidney ciliogenesis and cellular quiescence". Plos Genetics. 3 (1): e8. doi:10.1371/journal.pgen.0030008. PMC 1761047. PMID 17206865.
  9. ^ Munonye I, Sanu KP, Islam N, Gadaga C, Choudhury AR (November 2021). "A review of Alström syndrome: a rare monogenic ciliopathy". Intractable & Rare Diseases Research. 10 (4): 257–262. doi:10.5582/irdr.2021.01113. ISSN 2186-3644. PMC 8630466. PMID 34877237.
  10. ^ Munonye I, Sanu KP, Islam N, Gadaga C, Choudhury AR (November 2021). "A review of Alström syndrome: a rare monogenic ciliopathy". Intractable & Rare Diseases Research. 10 (4): 257–262. doi:10.5582/irdr.2021.01113. ISSN 2186-3644. PMC 8630466. PMID 34877237.
  11. ^ Potter DL, Liao TD, King KN, Ortiz PA, Monu SR (2023-10-01). "Role of Alström syndrome 1 in the regulation of glomerular hemodynamics". American Journal of Physiology. Renal Physiology. 325 (4): F418 – F425. doi:10.1152/ajprenal.00017.2023. ISSN 1522-1466. PMC 10639022. PMID 37560774.
  12. ^ Hearn T, Renforth GL, Spalluto G, Hanley NA, Piper K, Brickwood S, et al. (May 2002). "Mutation of ALMS1, a large gene with a tandem repeat encoding 47 amino acids, causes Alström syndrome". Nature Genetics. 31 (1): 79–83. doi:10.1038/ng874. PMID 11941370.

Further reading

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This article incorporates text from the United States National Library of Medicine, which is in the public domain.