RESUMO
In addition to their role in motility, eukaryotic cilia serve as a distinct compartment for signal transduction and regulatory sequestration of biomolecules. Recent genetic and biochemical studies have revealed an extraordinary diversity of protein complexes involved in the biogenesis of cilia during each cell cycle. Mutations in components of these complexes are at the heart of human ciliopathies such as Nephronophthisis (NPHP), Meckel-Gruber syndrome (MKS), Bardet-Biedl syndrome (BBS) and Joubert syndrome (JBTS). Despite intense studies, proteins in some of these complexes, such as the NPHP1-4-8 and the MKS, remain poorly understood. Using a combination of computational analyses we studied these complexes to identify novel domains in them which might throw new light on their functions and evolutionary origins. First, we identified both catalytically active and inactive versions of transglutaminase-like (TGL) peptidase domains in key ciliary/centrosomal proteins CC2D2A/MKS6, CC2D2B, CEP76 and CCDC135. These ciliary TGL domains appear to have originated from prokaryotic TGL domains that act as peptidases, either in a prokaryotic protein degradation system with the MoxR AAA+ ATPase, the precursor of eukaryotic dyneins and midasins, or in a peptide-ligase system with an ATP-grasp enzyme comparable to tubulin-modifying TTL proteins. We suggest that active ciliary TGL proteins are part of a cilia-specific peptidase system that might remove tubulin modifications or cleave cilia- localized proteins, while the inactive versions are likely to bind peptides and mediate key interactions during ciliogenesis. Second, we observe a vast radiation of C2 domains, which are key membrane-localization modules, in multiple ciliary proteins, including those from the NPHP1-4-8 and the MKS complexes, such as CC2D2A/MKS6, RPGRIP1, RPGRIP1L, NPHP1, NPHP4, C2CD3, AHI1/Jouberin and CEP76, most of which can be traced back to the last common eukaryotic ancestor. Identification of these TGL and C2 domains aid in the proper reconstruction of the Y-shaped linkers, which are key structures in the transitional zone of cilia, by allowing precise prediction of the multiple membrane-contacting and protein-protein interaction sites in these structures. These findings help decipher key events in the evolutionary separation of the ciliary and nuclear compartments in course of the emergence of the eukaryotic cell.
Assuntos
Membrana Celular/genética , Cílios/genética , Células Epiteliais/metabolismo , Peptídeo Hidrolases/química , Transglutaminases/química , Anormalidades Múltiplas , Sequência de Aminoácidos , Animais , Síndrome de Bardet-Biedl/enzimologia , Síndrome de Bardet-Biedl/genética , Evolução Biológica , Membrana Celular/enzimologia , Doenças Cerebelares/enzimologia , Doenças Cerebelares/genética , Cerebelo/anormalidades , Cílios/metabolismo , Transtornos da Motilidade Ciliar/enzimologia , Transtornos da Motilidade Ciliar/genética , Encefalocele/enzimologia , Encefalocele/genética , Células Epiteliais/citologia , Anormalidades do Olho/enzimologia , Anormalidades do Olho/genética , Humanos , Doenças Renais Císticas/congênito , Doenças Renais Císticas/enzimologia , Doenças Renais Císticas/genética , Dados de Sequência Molecular , Mutação , Peptídeo Hidrolases/genética , Peptídeo Hidrolases/metabolismo , Filogenia , Doenças Renais Policísticas/enzimologia , Doenças Renais Policísticas/genética , Estrutura Terciária de Proteína , Retina/anormalidades , Retina/enzimologia , Retinose Pigmentar , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transglutaminases/genética , Transglutaminases/metabolismoRESUMO
A total of 111 amniotic fluid samples, clear or blood stained, with elevated levels of alpha-fetoprotein and acetylcholinesterase was analysed by immunoassays specific for acetylcholinesterase and butyrylcholinesterase and the acetylcholinesterase/butyrylcholinesterase-ratios determined. Samples from 40 pregnancies associated with anencephaly, 47 pregnancies associated with open spina bifida or encephalocele and six pregnancies with fetal intrauterine death or miscarriage all had ratios of greater than 0.14. All 11 pregnancies with fetal ventral wall defects had ratios less than 0.14 as had four pregnancies with normal outcome and elevated levels of alpha-fetoprotein and acetylcholinesterase. Three fetuses with both open spina bifida and ventral wall defects were associated with ratios above 0.14. These results suggest that immunochemical determination of acetylcholinesterase and butyrylcholinesterase can be used to distinguish pregnancies complicated by anencephaly, open spina bifida, encephalocele and miscarriage from those with ventral wall defects and samples with false positive elevated levels of alpha-fetoprotein and acetylcholinesterase. The procedure is accurate and simple to carry out and well suited to routine use in a clinical chemistry laboratory.
Assuntos
Acetilcolinesterase/análise , Líquido Amniótico/enzimologia , Butirilcolinesterase/análise , Anormalidades Congênitas/diagnóstico , Doenças Fetais/diagnóstico , Aborto Espontâneo/enzimologia , Anencefalia/enzimologia , Diagnóstico Diferencial , Encefalocele/enzimologia , Feminino , Morte Fetal/enzimologia , Cardiopatias Congênitas/enzimologia , Humanos , Imunoensaio/métodos , Gravidez , Diagnóstico Pré-Natal , Disrafismo Espinal/enzimologia , alfa-Fetoproteínas/análiseRESUMO
We examined the time course of CK and its isoenzymes in 15 patients with severe ischemic stroke. Patients with cerebral transtentorial herniation (n = 7) had the highest CK-BB activity during herniation (1.54 +/- 0.6 U/L, mean +/- SD; range: 1.0-2.6 U/L). These values were distinctly above the values of a control group of 20 patients with non-neurological diseases (0.39 +/- 0.2 U/L, mean +/- SD). In patients with smaller lesions without herniation (n = 8) the maximum CK-BB increase was lower (0.56 +/- 0.26 U/L, mean +/- SD).
