The structural basis for mRNA recognition and cleavage by the ribosome-dependent endonuclease RelE.

Translational control is widely used to adjust gene expression levels. During the stringent response in bacteria, mRNA is degraded on the ribosome by the ribosome-dependent endonuclease, RelE. The molecular basis for recognition of the ribosome and mRNA by RelE and the mechanism of cleavage are unknown. Here, we present crystal structures of E. coli RelE in isolation (2.5 A) and bound to programmed Thermus thermophilus 70S ribosomes before (3.3 A) and after (3.6 A) cleavage. RelE occupies the A site and causes cleavage of mRNA after the second nucleotide of the codon by reorienting and activating the mRNA for 2'-OH-induced hydrolysis. Stacking of A site codon bases with conserved residues in RelE and 16S rRNA explains the requirement for the ribosome in catalysis and the subtle sequence specificity of the reaction. These structures provide detailed insight into the translational regulation on the bacterial ribosome by mRNA cleavage.

Incidence, prevalence, and trends in polycystic ovary syndrome diagnosis: a United States population-based study from 2006 to 2019.

BACKGROUND: Polycystic ovary syndrome is the most common endocrine disorder in women of reproductive age, yet US incidence estimates do not exist, and prevalence estimates vary widely. OBJECTIVE: A population-based US study estimated the incidence, prevalence, and trends of polycystic ovary syndrome by age, race and ethnicity, and diagnosing provider type. STUDY DESIGN: A retrospective cohort study of patients enrolled in Kaiser Permanente Washington from 2006 to 2019 was conducted. All members identified as female, aged 16 to 40 years with at least 3 years of enrollment and at least 1 healthcare encounter during that time, were eligible for inclusion. Individuals were excluded if they had a history of oophorectomy or hysterectomy. Polycystic ovary syndrome cases were identified using the International Classification of Diseases diagnosis codes (International Classification of Diseases, Ninth Revision, 256.4 or International Classification of Diseases, Tenth Revision, E28.2). Individuals with a polycystic ovary syndrome diagnosis before study entry were excluded from incidence rate estimations. The incidence rates were adjusted by age using direct standardization to the 2010 US census data. Temporal trends in incidence were assessed using weighted linear regression (overall) and Poisson regression (by age, race and ethnicity, and provider type). Prevalent cases were defined as patients with a polycystic ovary syndrome diagnosis at any time before the end of 2019. Medical record review of 700 incident cases diagnosed in 2011-2019 was performed to validate incident cases identified by International Classification of Diseases codes using the Rotterdam criteria. RESULTS: Among 177,527 eligible patients who contributed 586,470 person-years, 2491 incident polycystic ovary syndrome cases were identified. The mean age at diagnosis was 26.9 years, and the mean body mass index was 31.6 kg/m2. Overall incidence was 42.5 per 10,000 person-years; the rates were similar over time but increased in individuals aged 16 to 20 years from 31.0 to 51.9 per 10,000 person-years (P=.01) and decreased among those aged 26 to 30 years from 82.8 to 45.0 per 10,000 person-years (P=.02). A small decreasing temporal trend in incidence rates was only observed among non-Hispanic White individuals (P=.01). The incidence rates by diagnosing provider type varied little over time. Among the 58,241 patients who contributed person-time in 2019, 3036 (5.2%) had a polycystic ovary syndrome International Classification of Diseases diagnosis code; the prevalence was the highest among the Hawaiian and Pacific Islander group (7.6%) followed by Native American and Hispanic groups. Medical record review classified 60% as definite or probable incident, 14% as possible incident, and 17% as prevalent polycystic ovary syndrome. The overall positive predictive value of polycystic ovary syndrome International Classification of Diseases diagnosis code for identifying definite, probable, or possible incident polycystic ovary syndrome was 76% (95% confidence interval, 72%-79%). CONCLUSION: Among a cohort of nonselected females in the United States, we observed stable rates of incident polycystic ovary syndrome diagnoses over time. The incidence of polycystic ovary syndrome was 4- to 5-fold greater than reported for the United Kingdom. The prevalence of polycystic ovary syndrome (5.2%) was almost double before the published US estimates (2.9%) based on the International Classification of Diseases codes. Race and ethnicity and provider type did not seem to have a major impact on temporal rates. Incident diagnoses increased over time in younger and decreased in older age groups, perhaps related to shifting practice patterns with greater awareness among practitioners of the impact of polycystic ovary syndrome on long-term health outcomes and improved prevention efforts. Moreover, increasing obesity rates may be a factor driving the earlier ages at diagnosis.

Taking the Next Steps in Regenerative Rehabilitation: Establishment of a New Interdisciplinary Field.

The growing field of regenerative rehabilitation has great potential to improve clinical outcomes for individuals with disabilities. However, the science to elucidate the specific biological underpinnings of regenerative rehabilitation-based approaches is still in its infancy and critical questions regarding clinical translation and implementation still exist. In a recent roundtable discussion from International Consortium for Regenerative Rehabilitation stakeholders, key challenges to progress in the field were identified. The goal of this article is to summarize those discussions and to initiate a broader discussion among clinicians and scientists across the fields of regenerative medicine and rehabilitation science to ultimately progress regenerative rehabilitation from an emerging field to an established interdisciplinary one. Strategies and case studies from consortium institutions-including interdisciplinary research centers, formalized courses, degree programs, international symposia, and collaborative grants-are presented. We propose that these strategic directions have the potential to engage and train clinical practitioners and basic scientists, transform clinical practice, and, ultimately, optimize patient outcomes.

Unusual base pairing during the decoding of a stop codon by the ribosome.

During normal translation, the binding of a release factor to one of the three stop codons (UGA, UAA or UAG) results in the termination of protein synthesis. However, modification of the initial uridine to a pseudouridine (Ψ) allows efficient recognition and read-through of these stop codons by a transfer RNA (tRNA), although it requires the formation of two normally forbidden purine-purine base pairs. Here we determined the crystal structure at 3.1 Å resolution of the 30S ribosomal subunit in complex with the anticodon stem loop of tRNA(Ser) bound to the ΨAG stop codon in the A site. The ΨA base pair at the first position is accompanied by the formation of purine-purine base pairs at the second and third positions of the codon, which show an unusual Watson-Crick/Hoogsteen geometry. The structure shows a previously unsuspected ability of the ribosomal decoding centre to accommodate non-canonical base pairs.

Mental health of African asylum-seekers and refugees in Hong Kong: using the social determinants of health framework.

BACKGROUND: Hong Kong is non-signatory to the 1951 Refugee Convention and its 1967 Protocol, and has no systematic domestic policies committed to the rights of asylum-seekers and refugees (ASRs). This creates a tenuous setting for African ASRs there. This study explored how mapped social determinates of health has impacted the mental health and wellbeing of African ASR's in Hong Kong. METHODS: A cross-sectional survey was carried out with 374 African ASRs. The survey comprised of: (a) socio-demographics; (b) health status; (c) health behaviours; and, (d) social experiences. Associations between social determinants of health and depression screen were explored and multivariable regression analysis was conducted. RESULTS: Majority of participants were 18-37 years old (79.7%), male (77.2%), single (66.4%) and educated (60.9% high school and above). Over a third (36.1%) screened positive for depression. Analyses revealed that living with family reduced the odds of a positive depression screen (OR = 0.25, 95%CI = 0.07-0.88). Those perceiving their health to be "Poor" were 5.78 times as likely to be screened for depression. Additionally, those with higher scores on the discrimination scale were more likely to have positive depression screen (OR = 1.17, 95%CI = 1.10-1.24). CONCLUSION: A significant proportion of African ASRs in Hong Kong exhibits depressive symptoms. A complex interaction combining both social and perceptions of health and discrimination in the host society is likely exacerbated by their ASR status. The use of community support groups or even re-examination of the family reunification laws could improve the mental health and wellbeing of African ASRs in Hong Kong.

A lost tribe in the city: health status and needs of African asylum seekers and refugees in Hong Kong.

BACKGROUND: Hong Kong's resistance to be a signatory of the 1951 Geneva Convention and lack of domestic policies in this area has resulted in restrictions on access to healthcare amongst asylum seekers and refugees (ASRs). Using social determinants of health framework this study sought to identify health practices, problems and needs of African ASRs in Hong Kong. METHODS: A cross-sectional survey comprising of six domains including health status, health-seeking behaviour and social experience targeted at adult African ASRs in Hong Kong was conducted through three local non-governmental organisations between February and April 2013. Outpatient care and inpatient care in the past 12 months were used as proxy measures of general and severe ill health respectively. Associations between the determinants of health factors with general or severe health was explored through logistic regressions. RESULTS: Majority of 374 participants were young, single, educated males having been in Hong Kong for over 5 years. A third of ARS (36.1 %) screened positive for depression. Most reported problems related to basic necessities (64.7-78.6 %) and access to health services (72.2 %). ASRs with relatively less education, health awareness or higher risk behaviours were less likely to have obtained outpatient or inpatient services. African ASRs reporting problems with case officers (aOR = 2.80; 95 % CI = 1.35-5.79) or illness in the past 30 days (aOR = 6.00; 95 % CI = 2.94-12.25) were more likely to report general ill health. Similarly, problems with the case officers (aOR = 3.76; 95 % CI = 1.97-7.18) and self-reported illness in the past 30 days (a​OR = 3.32; 95 % CI= 1.68-6.57) were also significantly associated with severe ill health. At the health system level, those who reported experiencing difficulties accessing the medical services in Hong Kong are 3.29 (95 % CI = 1.48-7.31) and 4.12 (95 % CI = 1.73-9.79) times as likely to report general and severe ill health respectively. CONCLUSION: The host government should have moral and ethical obligations to attend to the health needs of ASRs. Evidently a number of structural and health system factors have significantly impacted the health of African ASRs in Hong Kong. Changes to current policies regarding how African ASRs are handled whilst in Hong Kong but, more immediately, improvements in healthcare access are needed.

The ribosome triggers the stringent response by RelA via a highly distorted tRNA.

The bacterial stringent response links nutrient starvation with the transcriptional control of genes. This process is initiated by the stringent factor RelA, which senses the presence of deacylated tRNA in the ribosome as a symptom of amino-acid starvation to synthesize the alarmone (p)ppGpp. Here we report a cryo-EM study of RelA bound to ribosomes bearing cognate, deacylated tRNA in the A-site. The data show that RelA on the ribosome stabilizes an unusual distorted form of the tRNA, with the acceptor arm making contact with RelA and far from its normal location in the peptidyl transferase centre.

Crystal structure of the hybrid state of ribosome in complex with the guanosine triphosphatase release factor 3.

Protein release factor 3 (RF3), a guanosine triphosphatase, binds to ribosome after release of the nascent peptide and promotes dissociation of the class I release factors during the termination of protein synthesis. Here we present the crystal structure of the 70S ribosome with RF3 in the presence of a nonhydrolyzable GTP analogue, guanosine 5'-ß,γ-methylenetriphosphate (GDPCP), refined to 3.8 Å resolution. The structure shows that the subunits of the ribosome are rotated relative to each other compared to the canonical state, resulting in a P/E hybrid state for the transfer RNA. The substantial conformational rearrangements in the complex are described and suggest how RF3, by stabilizing the hybrid state of the ribosome, facilitates the dissociation of class I release factors.

Risk Factors for Incident Polycystic Ovary Syndrome Diagnosis.

Objective: While highly prevalent, risk factors for incident polycystic ovary syndrome (PCOS) are poorly delineated. Using a population-based cohort, we sought to identify predictors of incident PCOS diagnosis. Materials and Methods: A matched case-control analysis was completed utilizing patients enrolled in Kaiser Permanente Washington from 2006 to 2019. Inclusion criteria included female sex, age 16-40 years, and ≥3 years of prior enrollment with ≥1 health care encounter. PCOS cases were identified using International Classification of Diseases codes. For each incident case (n = 2,491), 5 patients without PCOS (n = 12,455) were matched based on birth year and enrollment status. Potential risk factors preceding diagnosis included family history of PCOS, premature menarche, parity, race, weight gain, obesity, valproate use, metabolic syndrome, epilepsy, prediabetes, and types 1 and 2 diabetes. Potential risk factors for incident PCOS diagnosis were assessed with univariate and multivariable conditional logistic regressions. Results: Mean age of PCOS cases was 26.9 years (SD 6.8). PCOS cases, compared with non-PCOS, were more frequently nulliparous (70.9% versus 62.4%) and in the 3 years prior to index date were more likely to have obesity (53.8% versus 20.7%), metabolic syndrome (14.5% versus 4.3%), prediabetes (7.4% versus 1.6%), and type 2 diabetes (4.1% versus 1.7%) (p < 0.001 for all comparisons). In multivariable models, factors associated with higher risk for incident PCOS included the following: obesity (compared with nonobese) Class I-II (body-mass index [BMI], 30-40 kg/m2; odds ratio [OR], 3.8; 95% confidence interval [CI], 3.4-4.2), Class III (BMI > 40 kg/m2; OR, 7.5, 95% CI, 6.5-8.7), weight gain (compared with weight loss or maintenance) of 1-10% (OR, 1.7, 95% CI, 1.3-2.1), 10-20% (OR, 1.9; 95% CI, 1.5-2.4), and >20% (OR, 2.6; 95% CI, 1.9-3.6), prediabetes (OR, 2.7; 95% CI, 2.1-3.4), and metabolic syndrome (OR, 1.8: 95% CI, 1.5-2.1). Conclusion: Excess weight gain, obesity, and metabolic dysfunction may play a key role in the ensuing phenotypic expression of PCOS. Treatment and prevention strategies targeted at preventing weight gain in early reproductive years may help reduce the risk of this syndrome.

Data-driven automated classification algorithms for acute health conditions: applying PheNorm to COVID-19 disease.

OBJECTIVES: Automated phenotyping algorithms can reduce development time and operator dependence compared to manually developed algorithms. One such approach, PheNorm, has performed well for identifying chronic health conditions, but its performance for acute conditions is largely unknown. Herein, we implement and evaluate PheNorm applied to symptomatic COVID-19 disease to investigate its potential feasibility for rapid phenotyping of acute health conditions. MATERIALS AND METHODS: PheNorm is a general-purpose automated approach to creating computable phenotype algorithms based on natural language processing, machine learning, and (low cost) silver-standard training labels. We applied PheNorm to cohorts of potential COVID-19 patients from 2 institutions and used gold-standard manual chart review data to investigate the impact on performance of alternative feature engineering options and implementing externally trained models without local retraining. RESULTS: Models at each institution achieved AUC, sensitivity, and positive predictive value of 0.853, 0.879, 0.851 and 0.804, 0.976, and 0.885, respectively, at quantiles of model-predicted risk that maximize F1. We report performance metrics for all combinations of silver labels, feature engineering options, and models trained internally versus externally. DISCUSSION: Phenotyping algorithms developed using PheNorm performed well at both institutions. Performance varied with different silver-standard labels and feature engineering options. Models developed locally at one site also worked well when implemented externally at the other site. CONCLUSION: PheNorm models successfully identified an acute health condition, symptomatic COVID-19. The simplicity of the PheNorm approach allows it to be applied at multiple study sites with substantially reduced overhead compared to traditional approaches.

GTPase activation of elongation factor EF-Tu by the ribosome during decoding.

We have used single-particle reconstruction in cryo-electron microscopy to determine a structure of the Thermus thermophilus ribosome in which the ternary complex of elongation factor Tu (EF-Tu), tRNA and guanine nucleotide has been trapped on the ribosome using the antibiotic kirromycin. This represents the state in the decoding process just after codon recognition by tRNA and the resulting GTP hydrolysis by EF-Tu, but before the release of EF-Tu from the ribosome. Progress in sample purification and image processing made it possible to reach a resolution of 6.4 A. Secondary structure elements in tRNA, EF-Tu and the ribosome, and even GDP and kirromycin, could all be visualized directly. The structure reveals a complex conformational rearrangement of the tRNA in the A/T state and the interactions with the functionally important switch regions of EF-Tu crucial to GTP hydrolysis. Thus, the structure provides insights into the molecular mechanism of signalling codon recognition from the decoding centre of the 30S subunit to the GTPase centre of EF-Tu.

Structure of the 70S ribosome bound to release factor 2 and a substrate analog provides insights into catalysis of peptide release.

We report the crystal structure of release factor 2 bound to ribosome with an aminoacyl tRNA substrate analog at the ribosomal P site, at 3.1 A resolution. The structure shows that upon stop-codon recognition, the universally conserved GGQ motif packs tightly into the peptidyl transferase center. Nucleotide A2602 of 23S rRNA, implicated in peptide release, packs with the GGQ motif in release factor 2. The ribose of A76 of the peptidyl-tRNA adopts the C2'-endo conformation, and the 2' hydroxyl of A76 is within hydrogen-bond distance of the 2' hydroxyl of A2451. The structure suggests how a catalytic water can be coordinated in the peptidyl transferase center and, together with previous biochemical and computational data, suggests a model for how the ester bond between the peptidyl tRNA and the nascent peptide is hydrolyzed.

Modification of 16S ribosomal RNA by the KsgA methyltransferase restructures the 30S subunit to optimize ribosome function.

All organisms incorporate post-transcriptional modifications into ribosomal RNA, influencing ribosome assembly and function in ways that are poorly understood. The most highly conserved modification is the dimethylation of two adenosines near the 3' end of the small subunit rRNA. Lack of these methylations due to deficiency in the KsgA methyltransferase stimulates translational errors during both the initiation and elongation phases of protein synthesis and confers resistance to the antibiotic kasugamycin. Here, we present the X-ray crystal structure of the Thermus thermophilus 30S ribosomal subunit lacking these dimethylations. Our data indicate that the KsgA-directed methylations facilitate structural rearrangements in order to establish a functionally optimum subunit conformation during the final stages of ribosome assembly.

Crystal structure of the ribosome recycling factor bound to the ribosome.

In bacteria, disassembly of the ribosome at the end of translation is facilitated by an essential protein factor termed ribosome recycling factor (RRF), which works in concert with elongation factor G. Here we describe the crystal structure of the Thermus thermophilus RRF bound to a 70S ribosomal complex containing a stop codon in the A site, a transfer RNA anticodon stem-loop in the P site and tRNA(fMet) in the E site. The work demonstrates that structures of translation factors bound to 70S ribosomes can be determined at reasonably high resolution. Contrary to earlier reports, we did not observe any RRF-induced changes in bridges connecting the two subunits. This suggests that such changes are not a direct requirement for or consequence of RRF binding but possibly arise from the subsequent stabilization of a hybrid state of the ribosome.

PKMzeta maintains spatial, instrumental, and classically conditioned long-term memories.

How long-term memories are stored is a fundamental question in neuroscience. The first molecular mechanism for long-term memory storage in the brain was recently identified as the persistent action of protein kinase Mzeta (PKMzeta), an autonomously active atypical protein kinase C (PKC) isoform critical for the maintenance of long-term potentiation (LTP). PKMzeta maintains aversively conditioned associations, but what general form of information the kinase encodes in the brain is unknown. We first confirmed the specificity of the action of zeta inhibitory peptide (ZIP) by disrupting long-term memory for active place avoidance with chelerythrine, a second inhibitor of PKMzeta activity. We then examined, using ZIP, the effect of PKMzeta inhibition in dorsal hippocampus (DH) and basolateral amygdala (BLA) on retention of 1-d-old information acquired in the radial arm maze, water maze, inhibitory avoidance, and contextual and cued fear conditioning paradigms. In the DH, PKMzeta inhibition selectively disrupted retention of information for spatial reference, but not spatial working memory in the radial arm maze, and precise, but not coarse spatial information in the water maze. Thus retention of accurate spatial, but not procedural and contextual information required PKMzeta activity. Similarly, PKMzeta inhibition in the hippocampus did not affect contextual information after fear conditioning. In contrast, PKMzeta inhibition in the BLA impaired retention of classical conditioned stimulus-unconditioned stimulus (CS-US) associations for both contextual and auditory fear, as well as instrumentally conditioned inhibitory avoidance. PKMzeta inhibition had no effect on postshock freezing, indicating fear expression mediated by the BLA remained intact. Thus, persistent PKMzeta activity is a general mechanism for both appetitively and aversively motivated retention of specific, accurate learned information, but is not required for processing contextual, imprecise, or procedural information.

Family Caregiver Needs and Preferences for Virtual Training to Manage Behavioral and Psychological Symptoms of Dementia: Interview Study.

BACKGROUND: Behavioral and psychological symptoms of dementia (BPSD) are associated with increased stress, burden, and depression among family caregivers of people with dementia. STAR-Caregivers Virtual Training and Follow-up (STAR-VTF) is adapted from an evidence-based, in-person program that trains family caregivers to manage BPSD. We used a human-centered design approach to obtain feedback from family caregivers about STAR-VTF. The program will be evaluated using a pragmatic randomized trial. OBJECTIVE: The objective of the study was to understand the needs of family caregivers for improving BPSD management and the extent to which caregivers perceived that STAR-VTF could address those needs. METHODS: Between July and September 2019, we conducted 15 semistructured interviews with family caregivers of people with dementia who receive care at Kaiser Permanente Washington in the Seattle metropolitan area. We identified participants from electronic health records, primarily based on a prescription for antipsychotic medication for the person with dementia (a proxy for caregivers dealing with BPSD). We showed caregivers low-fidelity prototypes of STAR-VTF online self-directed materials and verbally described potential design elements. We obtained caregiver feedback on these elements, focusing on their needs and preferences and perceived barriers to using STAR-VTF. We used a hybrid approach of inductive and deductive coding and aggregated codes to develop themes. RESULTS: The idea of a virtual training program for learning to manage BPSD appealed to caregivers. They said health care providers did not provide adequate education in the early disease stages about the personality and behavior symptoms that can affect people with dementia. Caregivers found it unexpected and frustrating when the person with dementia began experiencing BPSD, symptoms they felt unprepared to manage. Accordingly, caregivers expressed a strong desire for the health care organization to offer programs such as STAR-VTF much sooner. Caregivers had already put considerable effort into problem solving challenging behaviors. They anticipated deriving less value from STAR-VTF at that point. Nonetheless, many were interested in the virtual aspect of the training due to the convenience of receiving help from home and the perception that help from a virtual program would be timelier than traditional service modalities (eg, face to face). Given caregivers' limited time, they suggested dividing the STAR-VTF content into chunks to review as time permitted. Caregivers were interested in having a STAR-VTF provider for additional support in managing challenging behaviors. Caregivers reported a preference for having the same coach for the program duration. CONCLUSIONS: Caregivers we interviewed would likely accept a virtual training program such as STAR-VTF to obtain information about BPSD and receive help managing it. Family caregivers anticipated deriving more value if STAR-VTF was offered earlier in the disease course.

Analysis of the 5'UTR of HCV genotype 3 grown in vitro in human B cells, T cells, and macrophages.

BACKGROUND: Previously, we have reported the isolation and molecular characterization of human Hepatitis C virus genotype 1 (HCV-1) from infected patients. We are now reporting an analysis of HCV obtained from patients infected with HCV genotype 3 (HCV-3) as diagnosed by clinical laboratories. RESULTS: HCV was cultured in vitro using our system. HCV RNA was isolated from patients' blood and from HCV cultured in various cell types for up to three months. The 5'UTR of these isolates were used for comparisons. Results revealed a number of sequence changes as compared to the serum RNA. The HCV RNA produced efficiently by infected macrophages, B-cells, and T-cells had sequences similar to HCV-1, which suggests that selection of the variants was performed at the level of macrophages. Virus with sequences similar to HCV-1 replicated better in macrophages than HCV having a 5'UTR similar to HCV-3. CONCLUSIONS: Although HCV-3 replicates in cell types such as B-cells, T-cells, and macrophages, it may require a different primary cell type for the same purpose. Therefore, in our opinion, HCV-3 does not replicate efficiently in macrophages, and patients infected with HCV-3 may contain a population of HCV-1 in their blood.

Cracking addiction the second time around: reconsolidation of drug-related memories.

One of the greatest challenges in the understanding and treatment of addiction is cue-elicited relapse to drug use. The present findings of Miller and Marshall and Lee et al. reported in this issue of Neuron demonstrate that retrieved drug-related memories undergo reconsolidation and thus suggest that these maladaptive associations may be more labile than previously thought.

Memory and addiction: shared neural circuitry and molecular mechanisms.

An important conceptual advance in the past decade has been the understanding that the process of drug addiction shares striking commonalities with neural plasticity associated with natural reward learning and memory. Basic mechanisms involving dopamine, glutamate, and their intracellular and genomic targets have been the focus of attention in this research area. These two neurotransmitter systems, widely distributed in many regions of cortex, limbic system, and basal ganglia, appear to play a key integrative role in motivation, learning, and memory, thus modulating adaptive behavior. However, many drugs of abuse exert their primary effects precisely on these pathways and are able to induce enduring cellular alterations in motivational networks, thus leading to maladaptive behaviors. Current theories and research on this topic are reviewed from an integrative systems perspective, with special emphasis on cellular, molecular, and behavioral aspects of dopamine D-1 and glutamate NMDA signaling, instrumental learning, and drug cue conditioning.

Accessories to addiction: G protein regulators play a key role in cocaine seeking and neuroplasticity.

The prefrontal cortex mediates many aspects of addiction. In this issue of Neuron, Bowers et al. demonstrate that an activator of G protein signaling (AGS3) is persistently upregulated in the prefrontal cortex after cessation of chronic cocaine treatment. Furthermore, they find that AGS3 is responsible for altered behavior, such as enhanced drug seeking, and altered neurotransmission in cocaine-treated rats, representing a novel therapeutic target.