TY - JOUR
T1 - Heterogeneous clinical phenotypes and cerebral malformations reflected by rotatin cellular dynamics
AU - Vandervore, Laura V.
AU - Schot, Rachel
AU - Kasteleijn, Esmee
AU - Oegema, Renske
AU - Stouffs, Katrien
AU - Gheldof, Alexander
AU - Grochowska, Martyna M.
AU - Van Der Sterre, Marianne L.T.
AU - Van Unen, Leontine M.A.
AU - Wilke, Martina
AU - Elfferich, Peter
AU - Van Der Spek, Peter J.
AU - Heijsman, Daphne
AU - Grandone, Anna
AU - Demmers, Jeroen A.A.
AU - Dekkers, Dick H.W.
AU - Slotman, Johan A.
AU - Kremers, Gert Jan
AU - Schaaf, Gerben J.
AU - Masius, Roy G.
AU - Van Essen, Anton J.
AU - Rump, Patrick
AU - Van Haeringen, Arie
AU - Peeters, Els
AU - Altunoglu, Umut
AU - Kalayci, Tugba
AU - Poot, Raymond A.
AU - Dobyns, William B.
AU - Bahi-Buisson, Nadia
AU - Verheijen, Frans W.
AU - Jansen, Anna C.
AU - Mancini, Grazia M.S.
N1 - Publisher Copyright:
© The Author(s) (2019). Published by Oxford University Press on behalf of the Guarantors of Brain.
PY - 2019/4/1
Y1 - 2019/4/1
N2 - Recessive mutations in RTTN, encoding the protein rotatin, were originally identified as cause of polymicrogyria, a cortical malformation. With time, a wide variety of other brain malformations has been ascribed to RTTN mutations, including primary microcephaly. Rotatin is a centrosomal protein possibly involved in centriolar elongation and ciliogenesis. However, the function of rotatin in brain development is largely unknown and the molecular disease mechanism underlying cortical malformations has not yet been elucidated. We performed both clinical and cell biological studies, aimed at clarifying rotatin function and pathogenesis. Review of the 23 published and five unpublished clinical cases and genomic mutations, including the effect of novel deep intronic pathogenic mutations on RTTN transcripts, allowed us to extrapolate the core phenotype, consisting of intellectual disability, short stature, microcephaly, lissencephaly, periventricular heterotopia, polymicrogyria and other malformations. We show that the severity of the phenotype is related to residual function of the protein, not only the level of mRNA expression. Skin fibroblasts from eight affected individuals were studied by high resolution immunomicroscopy and flow cytometry, in parallel with in vitro expression of RTTN in HEK293T cells. We demonstrate that rotatin regulates different phases of the cell cycle and is mislocalized in affected individuals. Mutant cells showed consistent and severe mitotic failure with centrosome amplification and multipolar spindle formation, leading to aneuploidy and apoptosis, which could relate to depletion of neuronal progenitors often observed in microcephaly. We confirmed the role of rotatin in functional and structural maintenance of primary cilia and determined that the protein localized not only to the basal body, but also to the axoneme, proving the functional interconnectivity between ciliogenesis and cell cycle progression. Proteomics analysis of both native and exogenous rotatin uncovered that rotatin interacts with the neuronal (non-muscle) myosin heavy chain subunits, motors of nucleokinesis during neuronal migration, and in human induced pluripotent stem cell-derived bipolar mature neurons rotatin localizes at the centrosome in the leading edge. This illustrates the role of rotatin in neuronal migration. These different functions of rotatin explain why RTTN mutations can lead to heterogeneous cerebral malformations, both related to proliferation and migration defects.
AB - Recessive mutations in RTTN, encoding the protein rotatin, were originally identified as cause of polymicrogyria, a cortical malformation. With time, a wide variety of other brain malformations has been ascribed to RTTN mutations, including primary microcephaly. Rotatin is a centrosomal protein possibly involved in centriolar elongation and ciliogenesis. However, the function of rotatin in brain development is largely unknown and the molecular disease mechanism underlying cortical malformations has not yet been elucidated. We performed both clinical and cell biological studies, aimed at clarifying rotatin function and pathogenesis. Review of the 23 published and five unpublished clinical cases and genomic mutations, including the effect of novel deep intronic pathogenic mutations on RTTN transcripts, allowed us to extrapolate the core phenotype, consisting of intellectual disability, short stature, microcephaly, lissencephaly, periventricular heterotopia, polymicrogyria and other malformations. We show that the severity of the phenotype is related to residual function of the protein, not only the level of mRNA expression. Skin fibroblasts from eight affected individuals were studied by high resolution immunomicroscopy and flow cytometry, in parallel with in vitro expression of RTTN in HEK293T cells. We demonstrate that rotatin regulates different phases of the cell cycle and is mislocalized in affected individuals. Mutant cells showed consistent and severe mitotic failure with centrosome amplification and multipolar spindle formation, leading to aneuploidy and apoptosis, which could relate to depletion of neuronal progenitors often observed in microcephaly. We confirmed the role of rotatin in functional and structural maintenance of primary cilia and determined that the protein localized not only to the basal body, but also to the axoneme, proving the functional interconnectivity between ciliogenesis and cell cycle progression. Proteomics analysis of both native and exogenous rotatin uncovered that rotatin interacts with the neuronal (non-muscle) myosin heavy chain subunits, motors of nucleokinesis during neuronal migration, and in human induced pluripotent stem cell-derived bipolar mature neurons rotatin localizes at the centrosome in the leading edge. This illustrates the role of rotatin in neuronal migration. These different functions of rotatin explain why RTTN mutations can lead to heterogeneous cerebral malformations, both related to proliferation and migration defects.
KW - MYH10
KW - RTTN
KW - centrosome amplification
KW - microcephaly
KW - mitosis
UR - http://www.scopus.com/inward/record.url?scp=85064285785&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85064285785&partnerID=8YFLogxK
U2 - 10.1093/brain/awz045
DO - 10.1093/brain/awz045
M3 - Article
C2 - 30879067
AN - SCOPUS:85064285785
SN - 0006-8950
VL - 142
SP - 867
EP - 884
JO - Brain
JF - Brain
IS - 4
ER -