Hernandez, A. B. | bioRxiv Science

bioRxiv2026

Antizyme regulates polyamine uptake via ATP13A3

Intracellular polyamine levels are tightly regulated and frequently elevated in cancer. While the regulation of polyamine synthesis is well characterized, the regulation of polyamine uptake is poorly understood. Here we identify ATP13A3 as a plasma membrane polyamine transporter. An increase in intracellular polyamine levels, due to polyamine supplementation or induction of polyamine synthesis, causes rapid internalization of the transporter and inhibition of polyamine uptake. Mechanistically, increased polyamine concentrations lead to expression of antizyme (AZ) which binds ATP13A3 and triggers its internalization. Mutations in the AZ binding site of ATP13A3 prevent AZ binding and lead to polyamine toxicity through uncontrolled polyamine influx. These findings establish ATP13A3 as a key polyamine transporter and provide a framework for targeting polyamine metabolism in cancer.

cell biology↗

bioRxiv2019

The Dreem Headband as an Alternative to Polysomnography for EEG Signal Acquisition and Sleep Staging

Despite the central role of sleep in our lives and the high prevalence of sleep disorders, sleep is still poorly understood. The development of ambulatory technologies capable of monitoring brain activity during sleep longitudinally is critical to advancing sleep science and facilitating the diagnosis of sleep disorders. We introduced the Dreem headband (DH) as an affordable, comfortable, and user-friendly alternative to polysomnography (PSG). The purpose of this study was to assess the signal acquisition of the DH and the performance of its embedded automatic sleep staging algorithms compared to the gold-standard clinical PSG scored by 5 sleep experts. Thirty-one subjects completed an over-night sleep study at a sleep center while wearing both a PSG and the DH simultaneously. We assessed 1) the EEG signal quality between the DH and the PSG, 2) the heart rate, breathing frequency, and respiration rate variability (RRV) agreement between the DH and the PSG, and 3) the performance of the DHs automatic sleep staging according to AASM guidelines vs. PSG sleep experts manual scoring. Results demonstrate a strong correlation between the EEG signals acquired by the DH and those from the PSG, and the signals acquired by the DH enable monitoring of alpha (r= 0.71 {+/-} 0.13), beta (r= 0.71 {+/-} 0.18), delta (r = 0.76 {+/-} 0.14), and theta (r = 0.61 {+/-} 0.12) frequencies during sleep. The mean absolute error for heart rate, breathing frequency and RRV was 1.2 {+/-} 0.5 bpm, 0.3 {+/-} 0.2 cpm and 3.2 {+/-} 0.6 %, respectively. Automatic Sleep Staging reached an overall accuracy of 83.5 {+/-} 6.4% (F1 score : 83.8 {+/-} 6.3) for the DH to be compared with an average of 86.4 {+/-} 8.0% (F1 score: 86.3 {+/-} 7.4) for the five sleep experts. These results demonstrate the capacity of the DH to both precisely monitor sleep-related physiological signals and process them accurately into sleep stages. This device paves the way for high-quality, large-scale, longitudinal sleep studies.

neuroscience↗