During adaptation to protein/amino acid (AA) limitation, the general control non‐derepressible 2 (GCN2) serine/threonine protein kinase initiates the amino acid response (AAR) by binding uncharged tRNAs, which activates its kinase activity. Subsequently, GCN2 phosphorylates eukaryotic initiation factor 2 (eIF2) leading to suppression of general protein synthesis, but induction of translation for specific mRNA species, including that for the transcription factor ATF4. ATF4 is a major effector of AAR‐induced transcription for many genes involved in restoring homeostasis or inducing apoptosis. GCN2 is currently the only well characterized sensor for AA deficiency in mammalian cells and the GCN2‐eIF2‐ATF4 pathway is considered the predominant AAR signaling mechanism. However, evidence from several laboratories has been published suggesting that GCN2‐independent AAR signaling exists. In this study, HepG2 human hepatoma clonal cell lines, expressing shRNA against GCN2, were generated to investigate the possibility of alternative AAR signaling mechanisms. Based on previous research, the MAPK pathways were likely candidates and therefore, were screened using chemical inhibitors. Using IL‐8 as a model MAPK‐responsive and AA‐responsive gene, it was established that c‐RAF/MEK/ERK signaling contributes to GCN2‐independent regulation of a wide spectrum of genes following AA limitation. Grant Funding Source: Supported by NIH, DK092062 and DK094729

24Zika virus (ZIKV) infections are an emerging health pandemic of significant medical importance. 25ZIKV appeared recently in the Americas from Africa via the South Pacific. The current outbreak 26 has garnered attention by exhibiting unique characteristics of devastating neurodevelopmental 27 defects in newborns of infected pregnant women. Current guidelines for ZIKV diagnostics 28 developed by the Center of Diseases Control and Prevention (CDC) consist of nucleic acid 29 testing, plaque reduction neutralization test (PRNT), and a serologic test for IgM detection. To 30better accommodate and comply with these guidelines, we developed a simultaneous on-chip 31 detection of ZIKV and anti-ZIKV antibodies using an array of nanowells. Using on-chip 32 microengraving, we were able to detect anti-ZIKV antibodies and their immunoglobulin isotypes. 33In parallel, applying on-chip real-time PCR with epifluorescence microscopy, we were able to 34 quantify ZIKV viral load as low as one copy. To test clinical samples of patients at the post-35 convalescent stage, we analyzed samples from 8 patients. The on-chip nanowells could 36 effectively identify antibodies that reacted against ZIKV envelope protein and their isotypes with 37 high sensitivity and specificity. The small sample requirement with high specificity and 38 sensitivity and combined molecular and serological tests could potentially be very advantageous 39 and beneficial in accurate detection of Zika infection for better disease monitoring and 40 management.41 42