The A_2A adenosine receptor rescues neuritogenesis impaired by p53 blockage via KIF2A, a kinesin family member

Abstract

The A2A adenosine receptor (A2AR) is a G-protein-coupled receptor. We previously reported that the C terminus of the A2AR binds to translin-associated protein X (TRAX) and modulates nerve growth factor (NGF)-evoked neurite outgrowth in PC12 cells. Herein, we show that neuritogenesis of primary hippocampal neurons requires p53 because blockage of p53 suppressed neurite outgrowth. The impaired neuritogenesis caused by p53 blockage was rescued by activation of the A2AR (designated the A2A rescue effect) in a TRAX-dependent manner. Importantly, suppression of a TRAX-interacting protein (kinesin heavy chain member 2A, KIF2A) inhibited the A2A rescue effect, whereas overexpression of KIF2A caused a rescue effect. Expression of a KIF2A fragment (KIF2A514), which disturbed the interaction between KIF2A and TRAX, blocked the rescue effect. Transient colocalization of TRAX and KIF2A was detected in the nucleus of PC12 cells upon NGF treatment. These data suggest that functional interaction between KIF2A and TRAX is critical for the A2A rescue effect. Moreover, p53 blockage during NGF treatment prevented the redistribution of KIF2A from the nucleus to the cytoplasmic region. Expression of a nuclear-retained KIF2A variant (NLS-KIF2A) did not rescue the impaired neurite outgrowth as did the wild-type KIF2A. Therefore, redistribution of KIF2A to the cytoplasmic fraction is a prerequisite for neurite outgrowth. Collectively, we demonstrate that KIF2A functions downstream of p53 to mediate neuritogenesis of primary hippocampal neurons and PC12 cells. Stimulation of the A2AR rescued neuritogenesis impaired by p53 blockage via an interaction between TRAX and KIF2A.

A central role of TRAX in the ATM-mediated DNA repair

“…18,22,24,25,27,[54][55][56] We demonstrate here that activated ATM is a new interacting protein of TRAX. The potential involvement of a few other TRAX-binding proteins (including Translin and C1D) in DNA repair is of great interest.…”

“…To identify the location at which TRAX exerts its protective effect, we created a TRAX mutant that lacks the nuclear localization signal (NLS; amino acids [11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] and is fused to a V5-tag (designated ΔNLS-V5). As shown in Figure 3d, ΔNLS-V5 was located mainly in the cytoplasmic region.…”

“…Permanent TRAX-knockdown PC12 cells were established by the transfection of a linearized pSUPERsiTRAX-875 construct, which was shown to markedly reduce the endogenous TRAX in PC12 cells. 24 The transfected PC12 cells were selected by G418 (500 mg/ml) to isolate permanent clones (designated PC12-TRAXi). To establish the control PC12 cell lines (designated PC12-pSUPER), the parental PC12 cells were transfected with a linearized pSUPER vector (Oligoengine, Seattle, WA, USA) and selected using G418 as described above.…”

“…[19][20][21][22] Independent to Translin, TRAX alone regulates axonal regeneration 23 and rescuing impaired neuronal differentiation caused by p53 blockade. 24,25 In response to DNA damage, TRAX interacts directly with C1D, a nuclear matrix protein participating in DNA repair. 26,27 Nonetheless, the exact role of how TRAX detects and repairs DNA damage is largely unknown.…”

Prenatal alcohol exposure alters expression of neurogenesis-related genes in an ex vivo cell culture model

“…Several of these genes have been studied in the context of alcohol exposure; for example, Adora2a , which encodes the A 2A receptor and is highly expressed in the adult striatum, has been implicated in alcohol use disorders and other addictive behaviors (Hack & Christie, 2003; Nam, Bruner, & Choi, 2013; Nam, Hinton, et al, 2013). Transient expression of A 2A during development of the brain aids in neuritogenesis and proliferation (Sun et al, 2010; Weaver, 1993); however, the role of A 2A in development after PAE has not been studied extensively. Additionally, A 2A activation leads to upregulation of VEGF expression, suggesting that the decreased mRNA levels of both of these genes after PAE may be connected in the proliferating NPC culture conditions (Escudero et al, 2013).…”