Kidins220/ARMS Modulates the Activity of Microtubule-regulating Proteins and Controls Neuronal Polarity and Development

Abstract

In order for neurons to perform their function, they must establish a highly polarized morphology characterized, in most of the cases, by a single axon and multiple dendrites. Herein we find that the evolutionarily conserved protein Kidins220 (kinase D-interacting substrate of 220-kDa), also known as ARMS (ankyrin repeat-rich membrane spanning), a downstream effector of protein kinase D and neurotrophin and ephrin receptors, regulates the establishment of neuronal polarity and development of dendrites. Kidins220/ARMS gain and loss of function experiments render severe phenotypic changes in the processes extended by hippocampal neurons in culture. Although Kidins220/ARMS early overexpression hinders neuronal development, its down-regulation by RNA interference results in the appearance of multiple longer axon-like extensions as well as aberrant dendritic arbors. We also find that Kidins220/ARMS interacts with tubulin and microtubule-regulating molecules whose role in neuronal morphogenesis is well established (microtubule-associated proteins 1b, 1a, and 2 and two members of the stathmin family). Importantly, neurons where Kidins220/ARMS has been knocked down register changes in the phosphorylation activity of MAP1b and stathmins. Altogether, our results indicate that Kidins220/ARMS is a key modulator of the activity of microtubuleregulating proteins known to actively regulate neuronal morphogenesis and suggest a mechanism by which it contributes to control neuronal development.Neuronal differentiation comprises several steps, among which the acquirement of a polarized axon-dendrite phenotype, with the corresponding asymmetrical distribution of proteins, is crucial. The morphological changes, followed by a neuron in order to polarize and form a single axon and multiple dendrites, are triggered by signaling cascades evoked by both intracellular and extracellular cues (1-4).Embryonic hippocampal neurons in culture constitute a model to study the mechanisms governing the establishment of polarity (2, 5, 6). These neurons undergo clear morphological changes during in vitro polarization. First, neurons attach to the plate and form lamellipodia and filopodia (stage 1). After several hours, they extend several minor immature neurites of apparent equivalent nature (stage 2) until one of these minor processes extends rapidly and becomes the axon (stage 3). The remaining neurites develop into dendrites (stage 4), after which neurons become morphologically and functionally mature (stage 5) (5, 6).During the early events of the establishment of polarity in this model, differences in local actin polymerization among the immature neurites play a crucial role in axonal determination (5, 7). In a similar manner, microtubule dynamics influence neuronal polarization, because local microtubule stabilization in one neurite specifies an axonal fate (8). Other known regulators of neuronal polarity and axon specification include proteins involved in polarized trafficking (4, 9, 10). However, how these different molecules are linked to t...

Kidins220/ARMS regulates Rac1-dependent neurite outgrowth by direct interaction with the RhoGEF Trio

“…Since most hippocampal neurons expressing Kidins220 1-402 did not bear neurites after 1 day in vitro, it is likely that the ankyrin repeats affects neurite initiation, which is important for both dendritic and axonal growth. This is in accordance with previous studies, which showed that Kidins220 regulates dendritic branching in vivo (Wu et al, 2009), and modulated the development of both axons and dendrites (Higuero et al, 2009). In summary, this experiment demonstrates that the inhibitory activity of the ankyrin-rich domain of Kidins220 on neurite outgrowth also occurs in hippocampal neurons, strongly suggesting that the pathway elucidated in PC12 cells has general validity and controls differentiation in primary neurons.…”

Protein kinase D: a new player among the signaling proteins that regulate functions in the nervous system

“…PKD1 phosphorylates the scaffold protein Kidins220 [55][56][57][58] . Kidins220 transportation from the TGN to the plasma membrane requires the autophosphorylation of PKD1 at Ser916.…”

Regulation of cell polarity by controlled proteolytic systems

“…Kinase D-interacting substrate of 220 kDa (Kidins220), also known as ankyrin repeat-rich membrane spanning (ARMS), is a protein expressed predominantly in neural tissues. Kidins220 is the fi rst known physiological substrate of protein kinase D (PKD) and has been shown to have a role in determining neuronal polarity (Higuero et al, 2010). Calpain proteolysis infl uences Kidins220 functions and thus may also infl uence neuronal polarity via the PKD pathway (Lopez-Menendez et al, 2009).…”