Aberrant activation of AMP-activated protein kinase contributes to the abnormal distribution of HuR in amyotrophic lateral sclerosis

Abstract

Distorted mRNA metabolism contributes to amyotrophic lateral sclerosis (ALS). The human antigen R (HuR) is a major mRNA stabilizer. We report that abnormal localization of HuR was associated with enhanced AMP-activated protein kinase (AMPK) activity in the motor neurons of ALS patients. Activation of AMPK changed the location of HuR in mouse motor neurons and in a motor neuron cell line via phosphorylation of importin-α1. Stimulation of the A2A adenosine receptor normalized the AMPK-evoked redistribution of HuR. This suggests that aberrant activation of AMPK in motor neurons disrupts the normal distribution of HuR, which might imbalance RNA metabolism and contribute to ALS pathogenesis.

Keywords: A(2A) adenosine receptor; AMP-activated protein kinase; Amyotrophic lateral sclerosis; Human antigen R; Importin-α1; cAMP.