Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

Of 11 genes involved in nonspecific X-linked mental retardation (MRX), three encode regulators or effectors of the Rho GTPases, suggesting an important role for Rho signaling in cognitive function. It remains unknown, however, how mutations in Rho-linked genes lead to MRX. Here we report that oligophrenin-1, a Rho-GTPase activating protein that is absent in a family affected with MRX, is required for dendritic spine morphogenesis. Using RNA interference and antisense RNA approaches, we show that knock-down of oligophrenin-1 levels in CA1 neurons in rat hippocampal slices significantly decreases spine length. This phenotype can be recapitulated using an activated form of RhoA and rescued by inhibiting Rho-kinase, indicating that reduced oligophrenin-1 levels affect spine length by increasing RhoA and Rho-kinase activities. We further demonstrate an interaction between oligophrenin-1 and the postsynaptic adaptor protein Homer. Our findings provide the first insight into how mutations in a Rho-linked MRX gene may compromise neuronal function.

Original publication




Journal article


Nat Neurosci

Publication Date





364 - 372


Animals, Cell Size, Cytoskeletal Proteins, Dendrites, Down-Regulation, GTPase-Activating Proteins, Hippocampus, Mental Retardation, X-Linked, Mice, Morphogenesis, Neurites, Neurons, Nuclear Proteins, Organ Culture Techniques, RNA Interference, RNA, Antisense, Rats, Synapses, Transfection