1Mol. Neurobiol. 2011 Jun 43: 180-91
PMID21271304
TitleCollapsin response mediator protein-2: an emerging pathologic feature and therapeutic target for neurodisease indications.
AbstractCollapsin response mediator protein-2 (DPYSL2 or CRMP2) is a multifunctional adaptor protein within the central nervous system. In the developing brain or cell cultures, CRMP2 performs structural and regulatory functions related to cytoskeletal dynamics, vesicle trafficking and synaptic physiology whereas CRMP2 functions in adult brain are still being elucidated. CRMP2 has been associated with several neuropathologic or psychiatric conditions including Alzheimer's disease (AD) and schizophrenia, either at the level of genetic polymorphisms; protein expression; post-translational modifications; or protein/protein interactions. In AD, CRMP2 is phosphorylated by glycogen synthase kinase-3? (GSK3?) and cyclin dependent protein kinase-5 (CDK5), the same kinases that act on tau protein in generating neurofibrillary tangles (NFTs). Phosphorylated CRMP2 collects in NFTs in association with the synaptic structure-regulating SRA1/WAVE1 (specifically Rac1-associated protein-1/WASP family verprolin-homologous protein-1) complex. This phenomenon could plausibly contribute to deficits in neural and synaptic structure that have been well documented in AD. This review discusses the essential biology of CRMP2 in the context of nascent data implicating CRMP2 perturbations as either a correlate of, or plausible contributor to, diverse neuropathologies. A discussion is made of recent findings that the atypical antidepressant tianeptine increases CRMP2 expression, whereas other, neuroactive small molecules including the epilepsy drug lacosamide and the natural brain metabolite lanthionine ketimine appear to bind CRMP2 directly with concomitant affects on neural structure. These findings constitute proofs-of-concept that pharmacological manipulation of CRMP2 is possible and hence, may offer new opportunities for therapy development against certain neurological diseases.
SCZ Keywordsschizophrenia
2Neuron 2013 Sep 79: 1169-82
PMID24050404
TitleCYFIP1 coordinates mRNA translation and cytoskeleton remodeling to ensure proper dendritic spine formation.
AbstractThe CYFIP1/SRA1 gene is located in a chromosomal region linked to various neurological disorders, including intellectual disability, autism, and schizophrenia. CYFIP1 plays a dual role in two apparently unrelated processes, inhibiting local protein synthesis and favoring actin remodeling. Here, we show that brain-derived neurotrophic factor (BDNF)-driven synaptic signaling releases CYFIP1 from the translational inhibitory complex, triggering translation of target mRNAs and shifting CYFIP1 into the WAVE regulatory complex. Active Rac1 alters the CYFIP1 conformation, as demonstrated by intramolecular FRET, and is key in changing the equilibrium of the two complexes. CYFIP1 thus orchestrates the two molecular cascades, protein translation and actin polymerization, each of which is necessary for correct spine morphology in neurons. The CYFIP1 interactome reveals many interactors associated with brain disorders, opening new perspectives to define regulatory pathways shared by neurological disabilities characterized by spine dysmorphogenesis.
SCZ Keywordsschizophrenia
3J. Neurosci. 2016 Feb 36: 1564-76
PMID26843638
TitleCyfip1 Regulates Presynaptic Activity during Development.
AbstractCopy number variations encompassing the gene encoding Cyfip1 have been associated with a variety of human diseases, including autism and schizophrenia. Here we show that juvenile mice hemizygous for Cyfip1 have altered presynaptic function, enhanced protein translation, and increased levels of F-actin. In developing hippocampus, reduced Cyfip1 levels serve to decrease paired pulse facilitation and increase miniature EPSC frequency without a change in amplitude. Higher-resolution examination shows these changes to be caused primarily by an increase in presynaptic terminal size and enhanced vesicle release probability. Short hairpin-mediated knockdown of Cyfip1 coupled with expression of mutant Cyfip1 proteins indicates that the presynaptic alterations are caused by dysregulation of the WAVE regulatory complex. Such dysregulation occurs downstream of Rac1 as acute exposure to Rac1 inhibitors rescues presynaptic responses in culture and in hippocampal slices. The data serve to highlight an early and essential role for Cyfip1 in the generation of normally functioning synapses and suggest a means by which changes in Cyfip1 levels could impact the generation of neural networks and contribute to abnormal and maladaptive behaviors.
Several developmental brain disorders have been associated with gene duplications and deletions that serve to increase or decrease levels of encoded proteins. Cyfip1 is one such protein, but the role it plays in brain development is poorly understood. We asked whether decreased Cyfip1 levels altered the function of developing synapses. The data show that synapses with reduced Cyfip1 are larger and release neurotransmitter more rapidly. These effects are due to Cyfip1's role in actin polymerization and are reversed by expression of a Cyfip1 mutant protein retaining actin regulatory function or by inhibiting Rac1. Thus, Cyfip1 has a more prominent early role regulating presynaptic activity during a stage of development when activity helps to define neural pathways.
SCZ Keywordsschizophrenia