DNAH5

Template:Short description An Error has occurred retrieving Wikidata item for infobox Dynein axonemal heavy chain 5 is a protein that in humans is encoded by the DNAH5 gene.

DNAH5 is a protein-coding gene.¹ It provides the instructions for synthesizing a protein that belongs to a microtubule-associated protein complex made of heavy, light and intermediate chains.² DNAH5 is responsible for making the heavy chain 5, found within the outer dynein arms of cilia.¹ It will function as a force generating protein by using ATP, producing the power stroke for cilia.³

During early development, the cilia found on the primitive node will beat in a directional pattern, sending signaling molecules to the left, this process will begin to establish the internal left-right asymmetry.³ Mutations in DNAH5 are linked to primary ciliary dyskinesia, an autosomal recessive disorder.⁴ This disorder is characterized by recurrent respiratory infections, infertility, and abnormal organ placement.¹ Non-functional DNAH5 proteins have been identified in individuals with primary ciliary dyskinesia and randomized left-right asymmetry.⁴

Associated Disorders and Knockout Studies

Mutations in DNAH5 are a common cause of primary ciliary dyskinesia, a rare autosomal recessive disorder that can lead to chronic respiratory infections, reduced fertility, and abnormal placement of internal organs^6,8. DNAH5 encodes a heavy chain protein found in the outer dynein arms of motile cilia, where it helps generate the force needed for normal ciliary beating⁶. When DNAH5 is mutated, cilia cannot beat properly, and this can disrupt the movement of fluid and signaling molecules during early embryonic development. Because of this disruption, left-right patterning may fail⁶., leading to situs inversus totalis, heterotaxy, or congenital heart defects⁷.

Studies in patients with DNAH5 mutations have also shown that the protein may be absent from the ciliary axoneme or incorrectly localized, which helps explain the loss of ciliary function. In mouse knockout models, disruption of DNAH5 produces similar laterality defects⁶, confirming that the gene is important for normal embryonic left-right asymmetry. These knockout studies also support the idea that defective nodal cilia movement is a major cause of the abnormal organ placement seen in affected humans⁹.

References

• DNAH5 gene - Genetics Home Reference - NIH. U.S. National Library of Medicine. https://medlineplus.gov/genetics/gene/dnah5/. Accessed April 15, 2019.
• Djakow J, Svobodová T, Hrach K, Uhlík J, Cinek O, Pohunek P. Effectiveness of sequencing selected exons of DNAH5 and DNAI1 in diagnosis of primary ciliary dyskinesia. Pediatric Pulmonology. 2012;47(9):864-875. doi:10.1002/ppul.22520.
• Andjelkovic M, Minic P, Vreca M, et al. Genomic profiling supports the diagnosis of primary ciliary dyskinesia and reveals novel candidate genes and genetic variants. PLOS ONE. 2018;13(10). doi:10.1371/journal.pone.0205422.
• Xu X, Gong P, Wen J. Clinical and genetic analysis of a family with Kartagener syndrome caused by novel DNAH5 mutations. Journal of Assisted Reproduction and Genetics. 2016;34(2):275-281. doi:10.1007/s10815-016-0849-3.

Further reading

• Jouannet P, Escaller D, Serres C, David G (1983). "Motility of human sperm without outer dynein arms". J. Submicrosc. Cytol. 15 (1): 67–71. PMID 6221120.
• Vaughan KT, Mikami A, Paschal BM, et al. (1997). "Multiple mouse chromosomal loci for dynein-based motility". Genomics. 36 (1): 29–38. doi:10.1006/geno.1996.0422. PMID 8812413.
• Neesen J, Koehler MR, Kirschner R, et al. (1997). "Identification of dynein heavy chain genes expressed in human and mouse testis: chromosomal localization of an axonemal dynein gene". Gene. 200 (1–2): 193–202. doi:10.1016/S0378-1119(97)00417-4. PMID 9373155.
• Nagase T, Kikuno R, Nakayama M, et al. (2001). "Prediction of the coding sequences of unidentified human genes. XVIII. The complete sequences of 100 new cDNA clones from brain which code for large proteins in vitro". DNA Res. 7 (4): 273–81. doi:10.1093/dnares/7.4.271. PMID 10997877.
• Omran H, Häffner K, Völkel A, et al. (2000). "Homozygosity mapping of a gene locus for primary ciliary dyskinesia on chromosome 5p and identification of the heavy dynein chain DNAH5 as a candidate gene". Am. J. Respir. Cell Mol. Biol. 23 (5): 696–702. doi:10.1165/ajrcmb.23.5.4257. PMID 11062149.
• Ota T, Suzuki Y, Nishikawa T, et al. (2004). "Complete sequencing and characterization of 21,243 full-length human cDNAs". Nat. Genet. 36 (1): 40–5. doi:10.1038/ng1285. PMID 14702039.
• Horváth J, Fliegauf M, Olbrich H, et al. (2005). "Identification and analysis of axonemal dynein light chain 1 in primary ciliary dyskinesia patients". Am. J. Respir. Cell Mol. Biol. 33 (1): 41–7. doi:10.1165/rcmb.2004-0335OC. PMID 15845866.
• Olbrich H, Horváth J, Fekete A, et al. (2006). "Axonemal localization of the dynein component DNAH5 is not altered in secondary ciliary dyskinesia". Pediatr. Res. 59 (3): 418–22. doi:10.1203/01.pdr.0000200809.21364.e2. PMID 16492982.
• Hornef N, Olbrich H, Horvath J, et al. (2006). "DNAH5 mutations are a common cause of primary ciliary dyskinesia with outer dynein arm defects". Am. J. Respir. Crit. Care Med. 174 (2): 120–6. doi:10.1164/rccm.200601-084OC. PMC 2662904. PMID 16627867.

External links

• GeneReviews/NIH/NCBI/UW entry on Primary Ciliary Dyskinesia