6nbw

Structural highlights

Disease

[ACTB_HUMAN] Defects in ACTB are a cause of dystonia juvenile-onset (DYTJ) [MIM:607371]. DYTJ is a form of dystonia with juvenile onset. Dystonia is defined by the presence of sustained involuntary muscle contraction, often leading to abnormal postures. DYTJ patients manifest progressive, generalized, dopa-unresponsive dystonia, developmental malformations and sensory hearing loss.^[1] Defects in ACTB are the cause of Baraitser-Winter syndrome type 1 (BRWS1) [MIM:243310]. A rare developmental disorder characterized by the combination of congenital ptosis, high-arched eyebrows, hypertelorism, ocular colobomata, and a brain malformation consisting of anterior-predominant lissencephaly. Other typical features include postnatal short stature and microcephaly, intellectual disability, seizures, and hearing loss.^[2] [PROF1_HUMAN] Defects in PFN1 are the cause of amyotrophic lateral sclerosis 18 (ALS18) [MIM:614808]. A neurodegenerative disorder affecting upper motor neurons in the brain and lower motor neurons in the brain stem and spinal cord, resulting in fatal paralysis. Sensory abnormalities are absent. The pathologic hallmarks of the disease include pallor of the corticospinal tract due to loss of motor neurons, presence of ubiquitin-positive inclusions within surviving motor neurons, and deposition of pathologic aggregates. The etiology of amyotrophic lateral sclerosis is likely to be multifactorial, involving both genetic and environmental factors. The disease is inherited in 5-10% of the cases.^[3]

Function

[ACTB_HUMAN] Actins are highly conserved proteins that are involved in various types of cell motility and are ubiquitously expressed in all eukaryotic cells. [PROF1_HUMAN] Binds to actin and affects the structure of the cytoskeleton. At high concentrations, profilin prevents the polymerization of actin, whereas it enhances it at low concentrations. By binding to PIP2, it inhibits the formation of IP3 and DG. Inhibits androgen receptor (AR) and HTT aggregation and binding of G-actin is essential for its inhibition of AR.^[4] [NAA80_HUMAN] N-alpha-acetyltransferase that specifically mediates the acetylation of the acidic amino terminus of processed forms of beta- and gamma-actin (ACTB and ACTG, respectively) (PubMed:30028079, PubMed:29581253). N-terminal acetylation of processed beta- and gamma-actin regulates actin filament depolymerization and elongation (PubMed:29581253). In vivo, preferentially displays N-terminal acetyltransferase activity towards acid N-terminal sequences starting with Asp-Asp-Asp and Glu-Glu-Glu (PubMed:30028079, PubMed:29581253). In vitro, shows high activity towards Met-Asp-Glu-Leu and Met-Asp-Asp-Asp (PubMed:10644992, PubMed:29581307). May act as a tumor suppressor (PubMed:10644992).^{[5] [6] [7] [8]}

References

1. ↑ Procaccio V, Salazar G, Ono S, Styers ML, Gearing M, Davila A, Jimenez R, Juncos J, Gutekunst CA, Meroni G, Fontanella B, Sontag E, Sontag JM, Faundez V, Wainer BH. A mutation of beta -actin that alters depolymerization dynamics is associated with autosomal dominant developmental malformations, deafness, and dystonia. Am J Hum Genet. 2006 Jun;78(6):947-60. Epub 2006 Apr 21. PMID:16685646 doi:S0002-9297(07)63917-2
2. ↑ Riviere JB, van Bon BW, Hoischen A, Kholmanskikh SS, O'Roak BJ, Gilissen C, Gijsen S, Sullivan CT, Christian SL, Abdul-Rahman OA, Atkin JF, Chassaing N, Drouin-Garraud V, Fry AE, Fryns JP, Gripp KW, Kempers M, Kleefstra T, Mancini GM, Nowaczyk MJ, van Ravenswaaij-Arts CM, Roscioli T, Marble M, Rosenfeld JA, Siu VM, de Vries BB, Shendure J, Verloes A, Veltman JA, Brunner HG, Ross ME, Pilz DT, Dobyns WB. De novo mutations in the actin genes ACTB and ACTG1 cause Baraitser-Winter syndrome. Nat Genet. 2012 Feb 26;44(4):440-4, S1-2. doi: 10.1038/ng.1091. PMID:22366783 doi:10.1038/ng.1091
3. ↑ Wu CH, Fallini C, Ticozzi N, Keagle PJ, Sapp PC, Piotrowska K, Lowe P, Koppers M, McKenna-Yasek D, Baron DM, Kost JE, Gonzalez-Perez P, Fox AD, Adams J, Taroni F, Tiloca C, Leclerc AL, Chafe SC, Mangroo D, Moore MJ, Zitzewitz JA, Xu ZS, van den Berg LH, Glass JD, Siciliano G, Cirulli ET, Goldstein DB, Salachas F, Meininger V, Rossoll W, Ratti A, Gellera C, Bosco DA, Bassell GJ, Silani V, Drory VE, Brown RH Jr, Landers JE. Mutations in the profilin 1 gene cause familial amyotrophic lateral sclerosis. Nature. 2012 Aug 23;488(7412):499-503. doi: 10.1038/nature11280. PMID:22801503 doi:10.1038/nature11280
4. ↑ Shao J, Welch WJ, Diprospero NA, Diamond MI. Phosphorylation of profilin by ROCK1 regulates polyglutamine aggregation. Mol Cell Biol. 2008 Sep;28(17):5196-208. doi: 10.1128/MCB.00079-08. Epub 2008 Jun, 23. PMID:18573880 doi:10.1128/MCB.00079-08
5. ↑ Zegerman P, Bannister AJ, Kouzarides T. The putative tumour suppressor Fus-2 is an N-acetyltransferase. Oncogene. 2000 Jan 6;19(1):161-3. doi: 10.1038/sj.onc.1203234. PMID:10644992 doi:http://dx.doi.org/10.1038/sj.onc.1203234
6. ↑ Drazic A, Aksnes H, Marie M, Boczkowska M, Varland S, Timmerman E, Foyn H, Glomnes N, Rebowski G, Impens F, Gevaert K, Dominguez R, Arnesen T. NAA80 is actin's N-terminal acetyltransferase and regulates cytoskeleton assembly and cell motility. Proc Natl Acad Sci U S A. 2018 Apr 24;115(17):4399-4404. doi:, 10.1073/pnas.1718336115. Epub 2018 Mar 26. PMID:29581253 doi:http://dx.doi.org/10.1073/pnas.1718336115
7. ↑ Goris M, Magin RS, Foyn H, Myklebust LM, Varland S, Ree R, Drazic A, Bhambra P, Stove SI, Baumann M, Haug BE, Marmorstein R, Arnesen T. Structural determinants and cellular environment define processed actin as the sole substrate of the N-terminal acetyltransferase NAA80. Proc Natl Acad Sci U S A. 2018 Mar 26. pii: 1719251115. doi:, 10.1073/pnas.1719251115. PMID:29581307 doi:http://dx.doi.org/10.1073/pnas.1719251115
8. ↑ Wiame E, Tahay G, Tyteca D, Vertommen D, Stroobant V, Bommer GT, Van Schaftingen E. NAT6 acetylates the N-terminus of different forms of actin. FEBS J. 2018 Sep;285(17):3299-3316. doi: 10.1111/febs.14605. Epub 2018 Aug 13. PMID:30028079 doi:http://dx.doi.org/10.1111/febs.14605