Targeted NGS gene panel identifies mutations in RSPH1 causing primary ciliary dyskinesia and a common mechanism for ciliary central pair agenesis due to radial spoke defects

For all motile eukaryotic cilia and flagella, beating is regulated by changes in intraciliary calcium concentration. Although the mechanism for calcium regulation is not understood, numerous studies have shown that calmodulin (CaM) is a key axonemal calcium sensor. Using anti-CaM antibodies and Chlamydomonas reinhardtii axonemal extracts, we precipitated a complex that includes four polypeptides and that specifically interacts with CaM in high [Ca2+]. One of the complex members, FAP221, is an orthologue of mammalian Pcdp1 (primary ciliary dyskinesia protein 1). Both FAP221 and mammalian Pcdp1 specifically bind CaM in high [Ca2+]. Reduced expression of Pcdp1 complex members in C. reinhardtii results in failure of the C1d central pair projection to assemble and significant impairment of motility including uncoordinated bends, severely reduced beat frequency, and altered waveforms. These combined results reveal that the central pair Pcdp1 (FAP221) complex is essential for control of ciliary motility.

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Novel genetic defects in primary ciliary dyskinesia affecting function of dynein arms and central pair apparatus

Cilia ◽

10.1186/2046-2530-1-s1-o1 ◽

2012 ◽

Vol 1 (S1) ◽

Author(s):

H Omran

Keyword(s):

Primary Ciliary Dyskinesia ◽

Genetic Defects ◽

Central Pair ◽

Dynein Arms ◽

Ciliary Dyskinesia

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Mutation of serine/threonine protein kinase 36 ( STK36 ) causes primary ciliary dyskinesia with a central pair defect

Human Mutation ◽

10.1002/humu.23261 ◽

2017 ◽

Vol 38 (8) ◽

pp. 964-969 ◽

Cited By ~ 33

Author(s):

Christine Edelbusch ◽

Sandra Cindrić ◽

Gerard W. Dougherty ◽

Niki T. Loges ◽

Heike Olbrich ◽

...

Keyword(s):

Protein Kinase ◽

Primary Ciliary Dyskinesia ◽

Central Pair ◽

Pair Defect ◽

Ciliary Dyskinesia

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Loss-of-Function Mutations in RSPH1 Cause Primary Ciliary Dyskinesia with Central-Complex and Radial-Spoke Defects

The American Journal of Human Genetics ◽

10.1016/j.ajhg.2013.07.013 ◽

2013 ◽

Vol 93 (3) ◽

pp. 561-570 ◽

Cited By ~ 91

Author(s):

Esther Kott ◽

Marie Legendre ◽

Bruno Copin ◽

Jean-François Papon ◽

Florence Dastot-Le Moal ◽

...

Keyword(s):

Primary Ciliary Dyskinesia ◽

Central Complex ◽

Loss Of Function ◽

Radial Spoke ◽

Ciliary Dyskinesia

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A novel hypomorphic allele of Spag17 causes primary ciliary dyskinesia phenotypes in mice

Disease Models & Mechanisms ◽

10.1242/dmm.045344 ◽

2020 ◽

Vol 13 (10) ◽

pp. dmm045344

Author(s):

Zakia Abdelhamed ◽

Marshall Lukacs ◽

Sandra Cindric ◽

Heymut Omran ◽

Rolf W. Stottmann

Keyword(s):

Cerebrospinal Fluid ◽

Fluid Flow ◽

Primary Ciliary Dyskinesia ◽

Human Condition ◽

Central Pair ◽

Cerebrospinal Fluid Flow ◽

Hypomorphic Allele ◽

Motile Cilia ◽

The Brain ◽

Ciliary Dyskinesia

ABSTRACTPrimary ciliary dyskinesia (PCD) is a human condition of dysfunctional motile cilia characterized by recurrent lung infection, infertility, organ laterality defects and partially penetrant hydrocephalus. We recovered a mouse mutant from a forward genetic screen that developed many of the hallmark phenotypes of PCD. Whole-exome sequencing identified this primary ciliary dyskinesia only (Pcdo) allele to be a nonsense mutation (c.5236A>T) in the Spag17 coding sequence creating a premature stop codon (K1746*). The Pcdo variant abolished several isoforms of SPAG17 in the Pcdo mutant testis but not in the brain. Our data indicate differential requirements for SPAG17 in different types of motile cilia. SPAG17 is essential for proper development of the sperm flagellum and is required for either development or stability of the C1 microtubule structure within the central pair apparatus of the respiratory motile cilia, but not the brain ependymal cilia. We identified changes in ependymal ciliary beating frequency, but these did not appear to alter lateral ventricle cerebrospinal fluid flow. Aqueductal stenosis resulted in significantly slower and abnormally directed cerebrospinal fluid flow, and we suggest that this is the root cause of the hydrocephalus. The Spag17Pcdo homozygous mutant mice are generally viable to adulthood but have a significantly shortened lifespan, with chronic morbidity. Our data indicate that the c.5236A>T Pcdo variant is a hypomorphic allele of Spag17 that causes phenotypes related to motile, but not primary, cilia. Spag17Pcdo is a useful new model for elucidating the molecular mechanisms underlying central pair PCD pathogenesis in the mouse.This article has an associated First Person interview with the first author of the paper.

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Structural insights into the cause of human RSPH4A primary ciliary dyskinesia

Molecular Biology of the Cell ◽

10.1091/mbc.e20-12-0806 ◽

2021 ◽

pp. mbc.E20-12-0806

Author(s):

Yanhe Zhao ◽

Justine Pinskey ◽

Jianfeng Lin ◽

Weining Yin ◽

Patrick R. Sears ◽

...

Keyword(s):

Primary Ciliary Dyskinesia ◽

Electron Tomography ◽

Three Dimensional ◽

Dimensional Structure ◽

Structural Basis ◽

Radial Spoke ◽

Radial Spokes ◽

Cilia And Flagella ◽

Tract Infections ◽

Ciliary Dyskinesia

Cilia and flagella are evolutionarily conserved eukaryotic organelles involved in cell motility and signaling. In humans, mutations in Radial Spoke Head Protein 4 homolog A ( RSPH4A) can lead to primary ciliary dyskinesia (PCD), a life-shortening disease characterized by chronic respiratory tract infections, abnormal organ positioning, and infertility. Despite its importance for human health, the location of RSPH4A in human cilia has not been resolved, and the structural basis of RSPH4A-/- PCD remains elusive. Here, we present the native, three-dimensional structure of RSPH4A-/- human respiratory cilia using samples collected non-invasively from a PCD patient. Using cryo-electron tomography and subtomogram averaging, we compared the structures of control and RSPH4A-/- cilia, revealing primary defects in two of the three radial spokes (RSs) within the axonemal repeat and secondary (heterogeneous) defects in the central pair complex. Similar to RSPH1-/- cilia, the radial spoke heads of RS1 and RS2, but not RS3, were missing in RSPH4A-/- cilia. However, RSPH4A-/- cilia also exhibited defects within the arch domains adjacent to the RS1 and RS2 heads, which were not observed with RSPH1 loss. Our results provide insight into the underlying structural basis for RSPH4A-/- PCD and highlight the benefits of applying cryo-ET directly to patient samples for molecular structure determination. [Media: see text]

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