scholarly journals Interaction of CDK5RAP2 with EB1 to Track Growing Microtubule Tips and to Regulate Microtubule Dynamics

2009 ◽  
Vol 20 (16) ◽  
pp. 3660-3670 ◽  
Author(s):  
Ka-Wing Fong ◽  
Shiu-Yeung Hau ◽  
Yik-Shing Kho ◽  
Yue Jia ◽  
Lisheng He ◽  
...  
Keyword(s):  
Rna Interference ◽  
Autosomal Recessive ◽  
Mutational Analysis ◽  
Microtubule Dynamics ◽  
Microtubule Assembly ◽  
Binding Motif ◽  
Primary Microcephaly ◽  
Evolution Of Mammals ◽  
Autosomal Recessive Primary Microcephaly

Mutations in cdk5rap2 are linked to autosomal recessive primary microcephaly, and attention has been paid to its function at centrosomes. In this report, we demonstrate that CDK5RAP2 localizes to microtubules and concentrates at the distal tips in addition to centrosomal localization. CDK5RAP2 interacts directly with EB1, a prototypic member of microtubule plus-end tracking proteins, and contains the basic and Ser-rich motif responsible for EB1 binding. The EB1-binding motif is conserved in the CDK5RAP2 sequences of chimpanzee, bovine, and dog but not in those of rat and mouse, suggesting a function gained during the evolution of mammals. The mutation of the Ile/Leu-Pro dipeptide within the motif abolishes EB1 interaction and plus-end attachment. In agreement with the mutational analysis, suppression of EB1 expression inhibits microtubule tip-tracking of CDK5RAP2. We have also found that the CDK5RAP2–EB1 complex regulates microtubule dynamics and stability. CDK5RAP2 depletion by RNA interference impacts the dynamic behaviors of microtubules. The CDK5RAP2–EB1 complex induces microtubule bundling and acetylation when expressed in cell cultures and stimulates microtubule assembly and bundle formation in vitro. Collectively, these results show that CDK5RAP2 targets growing microtubule tips in association with EB1 to regulate microtubule dynamics.

Spastin Interacts with CRMP2 to Regulate Neurite Outgrowth by Controlling Microtubule Dynamics through Phosphorylation Modifications

2020 ◽  
Vol 19 ◽  
Author(s):  
Sumei Li ◽  
Jifeng Zhang ◽  
Jiaqi Zhang ◽  
Jiong Li ◽  
Longfei Cheng ◽  
...  
Keyword(s):  
Neurite Outgrowth ◽  
Hippocampal Neurons ◽  
Neuronal Development ◽  
Phosphorylation Site ◽  
Microtubule Dynamics ◽  
Microtubule Assembly ◽  
C Terminus ◽  
Mediator Protein ◽  
Branch Formation

Aims: Our work aims to revealing the underlying microtubule mechanism of neurites outgrowth during neuronal development, and also proposes a feasible intervention pathway for reconstructing neural network connections after nerve injury. Background: Microtubule polymerization and severing are the basis for the neurite outgrowth and branch formation. Collapsin response mediator protein 2 (CRMP2) regulates axonal growth and branching as a binding partner of the tubulin heterodimer to promote microtubule assembly. And spastin participates in the growth and regeneration of neurites by severing microtubules into small segments. However, how CRMP2 and spastin cooperate to regulate neurite outgrowth by controlling the microtubule dynamics needs to be elucidated. Objective: To explore whether neurite outgrowth was mediated by coordination of CRMP2 and spastin. Method: Hippocampal neurons were cultured in vitro in 24-well culture plates for 4 days before being used to perform the transfection. Calcium phosphate was used to transfect the CRMP2 and spastin constructs and their control into the neurons. An interaction between CRMP2 and spastin was examined by using pull down, CoIP and immunofluorescence colocalization assays. And immunostaining was also performed to determine the morphology of neurites. Result: We first demonstrated that CRMP2 interacted with spastin to promote the neurite outgrowth and branch formation. Furthermore, our results identified that phosphorylation modification failed to alter the binding affinities of CRMP2 for spastin, but inhibited their binding to microtubules. CRMP2 interacted with the MTBD domain of spastin via its C-terminus, and blocking the binding sites of them inhibited the outgrowth and branch formation of neurites. In addition, we confirmed one phosphorylation site S210 at spastin in hippocampal neurons and phosphorylation spastin at site S210 promoted the neurite outgrowth but not branch formation by remodeling microtubules. Conclusion: Taken together, our data demonstrated that the interaction of CRMP2 and spastin is required for neurite outgrowth and branch formation and their interaction is not regulated by their phosphorylation.

scholarly journals A missense mutation in the PISA domain of HsSAS-6 causes autosomal recessive primary microcephaly in a large consanguineous Pakistani family

2014 ◽  
Vol 23 (22) ◽  
pp. 5940-5949 ◽  
Author(s):  
Muzammil A. Khan ◽  
Verena M. Rupp ◽  
Meritxell Orpinell ◽  
Muhammad S. Hussain ◽  
Janine Altmüller ◽  
...  
Keyword(s):  
Missense Mutation ◽  
Autosomal Recessive ◽  
Pakistani Family ◽  
Primary Microcephaly ◽  
Autosomal Recessive Primary Microcephaly

scholarly journals Regulation of Microtubule Dynamics by Bim1 and Bik1, the Budding Yeast Members of the EB1 and CLIP-170 Families of Plus-End Tracking Proteins

2010 ◽  
Vol 21 (12) ◽  
pp. 2013-2023 ◽  
Author(s):  
Kristina A. Blake-Hodek ◽  
Lynne Cassimeris ◽  
Tim C. Huffaker
Keyword(s):  
Budding Yeast ◽  
Family Members ◽  
Microtubule Dynamics ◽  
Microtubule Assembly ◽  
Microtubule Polymerization

Microtubule dynamics are regulated by plus-end tracking proteins (+TIPs), which bind microtubule ends and influence their polymerization properties. In addition to binding microtubules, most +TIPs physically associate with other +TIPs, creating a complex web of interactions. To fully understand how +TIPs regulate microtubule dynamics, it is essential to know the intrinsic biochemical activities of each +TIP and how +TIP interactions affect these activities. Here, we describe the activities of Bim1 and Bik1, two +TIP proteins from budding yeast and members of the EB1 and CLIP-170 families, respectively. We find that purified Bim1 and Bik1 form homodimers that interact with each other to form a tetramer. Bim1 binds along the microtubule lattice but with highest affinity for the microtubule end; however, Bik1 requires Bim1 for localization to the microtubule lattice and end. In vitro microtubule polymerization assays show that Bim1 promotes microtubule assembly, primarily by decreasing the frequency of catastrophes. In contrast, Bik1 inhibits microtubule assembly by slowing growth and, consequently, promoting catastrophes. Interestingly, the Bim1-Bik1 complex affects microtubule dynamics in much the same way as Bim1 alone. These studies reveal new activities for EB1 and CLIP-170 family members and demonstrate how interactions between two +TIP proteins influence their activities.

scholarly journals Previously described sequence variant in CDK5RAP2gene in a Pakistani family with autosomal recessive primary microcephaly

2007 ◽  
Vol 8 (1) ◽  
Author(s):  
Muhammad Jawad Hassan ◽  
Maryam Khurshid ◽  
Zahid Azeem ◽  
Peter John ◽  
Ghazanfar Ali ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Sequence Variant ◽  
Pakistani Family ◽  
Primary Microcephaly ◽  
Autosomal Recessive Primary Microcephaly

Mutation Analysis of the ASPM Gene in 18 Pakistani Families With Autosomal Recessive Primary Microcephaly

2009 ◽  
Vol 25 (6) ◽  
pp. 715-720 ◽  
Author(s):  
Rizwana Kousar ◽  
Hira Nawaz ◽  
Maryam Khurshid ◽  
Ghazanfer Ali ◽  
Saad Ullah Khan ◽  
...  
Keyword(s):  
Mutation Analysis ◽  
Autosomal Recessive ◽  
Primary Microcephaly ◽  
Autosomal Recessive Primary Microcephaly ◽  
Pakistani Families

Genetic studies of autosomal recessive primary microcephaly in 33 Pakistani families: novel sequence variants in ASPM gene

Neurogenetics ◽  
2006 ◽  
Vol 7 (2) ◽  
pp. 105-110 ◽  
Author(s):  
Asma Gul ◽  
Muhammad Jawad Hassan ◽  
Saqib Mahmood ◽  
Wenje Chen ◽  
Safa Rahmani ◽  
...  
Keyword(s):  
Autosomal Recessive ◽  
Sequence Variants ◽  
Primary Microcephaly ◽  
Genetic Studies ◽  
Autosomal Recessive Primary Microcephaly ◽  
Pakistani Families

scholarly journals Whole exome sequencing identifies a novel homozygous frameshift mutation in the ASPM gene, which causes microcephaly 5, primary, autosomal recessive

F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 2163
Author(s):  
Desaraju Suresh Bhargav ◽  
N. Sreedevi ◽  
N. Swapna ◽  
Soumya Vivek ◽  
Srinivas Kovvali
Keyword(s):  
Exome Sequencing ◽  
Autosomal Recessive ◽  
Frameshift Mutation ◽  
Protein Gene ◽  
Single Gene ◽  
Primary Microcephaly ◽  
Sequencing Technologies ◽  
Whole Exome ◽  
The Family ◽  
Autosomal Recessive Primary Microcephaly

Microcephaly is a genetically heterogeneous disorder and is one of the frequently notable conditions in paediatric neuropathology which exists either as a single entity or in association with other co-morbidities. More than a single gene is implicated in true microcephaly and the list is growing with the recent advancements in sequencing technologies. Using massive parallel sequencing, we identified a novel frame shift insertion in the abnormal spindle-like microcephaly-associated protein gene in a client with true autosomal recessive primary microcephaly.  Exome sequencing in the present case helped in identifying the true cause behind the disease, which helps in the premarital counselling for the sibling to avoid future recurrence of the disorder in the family.

scholarly journals CDK5RAP2 Is a Pericentriolar Protein That Functions in Centrosomal Attachment of the γ-Tubulin Ring Complex

2008 ◽  
Vol 19 (1) ◽  
pp. 115-125 ◽  
Author(s):  
Ka-Wing Fong ◽  
Yuk-Kwan Choi ◽  
Jerome B. Rattner ◽  
Robert Z. Qi
Keyword(s):  
Autosomal Recessive ◽  
Macromolecular Complex ◽  
Mitotic Spindles ◽  
Microtubule Nucleation ◽  
Primary Microcephaly ◽  
Conserved Sequence ◽  
Ring Complex ◽  
Pericentriolar Material ◽  
Related Proteins ◽  
Autosomal Recessive Primary Microcephaly

Microtubule nucleation and organization by the centrosome require γ-tubulin, a protein that exists in a macromolecular complex called the γ-tubulin ring complex (γTuRC). We report characterization of CDK5RAP2, a novel centrosomal protein whose mutations have been linked to autosomal recessive primary microcephaly. In somatic cells, CDK5RAP2 localizes throughout the pericentriolar material in all stages of the cell cycle. When overexpressed, CDK5RAP2 assembled a subset of centrosomal proteins including γ-tubulin onto the centrosomes or under the microtubule-disrupting conditions into microtubule-nucleating clusters in the cytoplasm. CDK5RAP2 associates with the γTuRC via a short conserved sequence present in several related proteins found in a range of organisms from fungi to mammals. The binding of CDK5RAP2 is required for γTuRC attachment to the centrosome but not for γTuRC assembly. Perturbing CDK5RAP2 function delocalized γ-tubulin from the centrosomes and inhibited centrosomal microtubule nucleation, thus leading to disorganization of interphase microtubule arrays and formation of anastral mitotic spindles. Together, CDK5RAP2 is a pericentriolar structural component that functions in γTuRC attachment and therefore in the microtubule organizing function of the centrosome. Our findings suggest that centrosome malfunction due to the CDK5RAP2 mutations may underlie autosomal recessive primary microcephaly.

Sign in / Sign up

Export Citation Format

Share Document