title: G8: a novel domain associated with polycystic kidney disease and non-syndromic hearing loss.
abstract: We report a novel protein domain-G8-which contains five repeated beta-strand pairs and is present in some disease-related proteins such as PKHD1, KIAA1199, TMEM2 as well as other uncharacterized proteins. Most G8-containing proteins are predicted to be membrane-integral or secreted. The G8 domain may be involved in extracellular ligand binding and catalysis. It has been reported that mis-sense mutations in the two G8 domains of human PKHD1 protein resulted in a less stable protein and are associated with autosomal-recessive polycystic kidney disease, indicating the importance of the domain structure. G8 is also present in the N-terminus of some non-syndromic hearing loss disease-related proteins such as KIAA1109 and TMEM2. Discovery of G8 domain will be important for the research of the structure/function of related proteins and beneficial for the development of novel therapeutics.
  
  
  BACKGROUND
  liangsp@hunnu.edu.cn
authors.affiliation: Key Laboratory of Protein Chemistry and Developmental Biology of Education Committee, College of Life Sciences, Hunan Normal University Changsha, People's Republic of China.
authors.forename: Quan-yuan
authors.initials: QY
authors.lastname: He
authors.forename: Xiang-hua
authors.initials: XH
authors.lastname: Liu
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.forename: David J
authors.initials: DJ
authors.lastname: Studholme
authors.forename: Xuan-wen
authors.initials: XW
authors.lastname: Li
authors.forename: Song-ping
authors.initials: SP
authors.lastname: Liang
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017124:Conserved Sequence; D019143:Evolution, Molecular; D006319:Hearing Loss, Sensorineural / Q000235:genetics / Q000378:metabolism*; D006821:Hyaluronoglucosaminidase; D008565:Membrane Proteins / Q000737:chemistry* / Q000235:genetics; D008969:Molecular Sequence Data; D007690:Polycystic Kidney Diseases / Q000235:genetics / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011506:Proteins / Q000737:chemistry* / Q000235:genetics; D011956:Receptors, Cell Surface / Q000737:chemistry* / Q000235:genetics; D016415:Sequence Alignment / Q000379:methods; D020539:Sequence Analysis, Protein / Q000379:methods*; D017386:Sequence Homology, Amino Acid; D013045:Species Specificity
chemical_list: C408224:CEMIP2 protein, human; D008565:Membrane Proteins; C451750:PKHD1 protein, human; D011506:Proteins; D011956:Receptors, Cell Surface; C491433:CEMIP protein, human; D006821:Hyaluronoglucosaminidase