ABSTRACT
TNK1 is a non-receptor tyrosine kinase with poorly understood biological function and regulation. Here, we identify TNK1 dependencies in primary human cancers. We also discover a MARK-mediated phosphorylation on TNK1 at S502 that promotes an interaction between TNK1 and 14-3-3, which sequesters TNK1 and inhibits its kinase activity. Conversely, the release of TNK1 from 14-3-3 allows TNK1 to cluster in ubiquitin-rich puncta and become active. Active TNK1 induces growth factor-independent proliferation of lymphoid cells in cell culture and mouse models. One unusual feature of TNK1 is a ubiquitin-association domain (UBA) on its C-terminus. Here, we characterize the TNK1 UBA, which has high affinity for poly-ubiquitin. Point mutations that disrupt ubiquitin binding inhibit TNK1 activity. These data suggest a mechanism in which TNK1 toggles between 14-3-3-bound (inactive) and ubiquitin-bound (active) states. Finally, we identify a TNK1 inhibitor, TP-5801, which shows nanomolar potency against TNK1-transformed cells and suppresses tumor growth in vivo.
Subject(s)
14-3-3 Proteins/genetics , Fetal Proteins/genetics , Lymphocytes/metabolism , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/genetics , Protein-Tyrosine Kinases/genetics , Ubiquitin/genetics , 14-3-3 Proteins/metabolism , A549 Cells , Animals , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Fetal Proteins/antagonists & inhibitors , Fetal Proteins/metabolism , Fusion Proteins, bcr-abl/genetics , Fusion Proteins, bcr-abl/metabolism , Gene Expression Regulation, Neoplastic , HEK293 Cells , Humans , Lymphocytes/drug effects , Lymphocytes/pathology , Mice , Phospholipase C gamma/genetics , Phospholipase C gamma/metabolism , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/mortality , Precursor B-Cell Lymphoblastic Leukemia-Lymphoma/pathology , Protein Binding , Protein Kinase Inhibitors/pharmacology , Protein-Tyrosine Kinases/antagonists & inhibitors , Protein-Tyrosine Kinases/metabolism , Pyrimidines/pharmacology , STAT3 Transcription Factor/genetics , STAT3 Transcription Factor/metabolism , STAT5 Transcription Factor/genetics , STAT5 Transcription Factor/metabolism , Signal Transduction , Survival Analysis , Tumor Burden/drug effects , Ubiquitin/metabolism , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND: About one third of youth in the United States are overweight or obese and African American youth are at an increased risk for pediatric overweight and obesity as well as their complications. Physical activity has been identified as one determinant of overweight and obesity, and school bullying has been found to be associated with decreased physical activity. Guided by the Transactional Stress and Coping Model, this study examines how school bullying might impact the physical activity of white and African American healthy weight and overweight youth. METHODS: Existing, nationally representative, and complex survey data (N = 4509) from the 2005-2006 United States Health Behavior in School-Aged Children (HBSC) were analyzed using multiple group structural equation modeling to evaluate study questions. RESULTS: Support for the hypothesized model was found such that bullying negatively impacted physical activity by way of increasing internalizing symptoms. Possible evidence for parental support, but not peer support, as a protective factor was also found. Results were generally similar for all groups, though some differences are discussed. CONCLUSION: School bullying is a risk factor for reduced physical activity, regardless of race-ethnicity and weight. Implications for school health professionals are discussed.
Subject(s)
Black or African American/psychology , Bullying/psychology , Exercise , Overweight/psychology , Parents/psychology , White People/psychology , Bullying/prevention & control , Ethnicity , Health Surveys , Humans , Peer Group , Racial Groups , Students , United StatesABSTRACT
In this study, we employed proteomics to identify mechanisms of posttranslational regulation on cell survival signaling proteins. We focused on Cu-Zn superoxide dismutase (SOD1), which protects cells from oxidative stress. We found that acylation of K122 on SOD1, while not impacting SOD1 catalytic activity, suppressed the ability of SOD1 to inhibit mitochondrial metabolism at respiratory complex I. We found that deacylase depletion increased K122 acylation on SOD1, which blocked the suppression of respiration in a K122-dependent manner. In addition, we found that acyl-mimicking mutations at K122 decreased SOD1 accumulation in mitochondria, initially hinting that SOD1 may inhibit respiration directly within the intermembrane space (IMS). However, surprisingly, we found that forcing the K122 acyl mutants into the mitochondria with an IMS-targeting tag did not recover their ability to suppress respiration. Moreover, we found that suppressing or boosting respiration levels toggled SOD1 in or out of the mitochondria, respectively. These findings place SOD1-mediated inhibition of respiration upstream of its mitochondrial localization. Lastly, deletion-rescue experiments show that a respiration-defective mutant of SOD1 is also impaired in its ability to rescue cells from toxicity caused by SOD1 deletion. Together, these data suggest a previously unknown interplay between SOD1 acylation, metabolic regulation, and SOD1-mediated cell survival.
Subject(s)
Acylation/physiology , Mitochondria/metabolism , Mitochondrial Membranes/metabolism , Mutation/genetics , Superoxide Dismutase-1/metabolism , Superoxide Dismutase/metabolism , Acylation/genetics , Amyotrophic Lateral Sclerosis/genetics , Animals , Humans , Mice , Mitochondria/genetics , Oxidative Stress/physiology , Superoxide Dismutase/genetics , Superoxide Dismutase-1/chemistry , Superoxide Dismutase-1/geneticsABSTRACT
The recruitment of culturally and linguistically diverse students to graduate programs is critical to the overall growth and development of school psychology as a field. Program websites serve as an effective recruitment tool for attracting prospective students, yet there is limited research on how school psychology programs use their websites to recruit diverse students. The purpose of this study was to evaluate whether school psychology program websites include sufficient levels of diversity-related content critical for attracting diverse applicants. The website content of 250 professional psychology programs (165 school psychology training programs and 85 clinical and counseling psychology programs) were examined for the presence of themes of diversity and multiculturalism that prospective racially/ethnically and linguistically diverse students deem important for selecting a graduate program. Results indicated that school psychology programs had less diversity-related content on their program's website relative to clinical and counseling psychology programs.' Implications for improving recruitment of racially/ethnically and linguistically diverse students through websites are discussed. (PsycINFO Database Record
Subject(s)
Cultural Diversity , Education, Graduate/organization & administration , Education, Professional/organization & administration , Internet/standards , Psychology, Educational/education , Curriculum , Education, Graduate/economics , Education, Professional/economics , Faculty , Humans , Psychology/statistics & numerical data , Psychology, Educational/economics , School Admission Criteria , Training Support , United StatesABSTRACT
The phospho-binding protein 14-3-3ζ acts as a signaling hub controlling a network of interacting partners and oncogenic pathways. We show here that lysines within the 14-3-3ζ binding pocket and protein-protein interface can be modified by acetylation. The positive charge on two of these lysines, Lys(49) and Lys(120), is critical for coordinating 14-3-3ζ-phosphoprotein interactions. Through screening, we identified HDAC6 as the Lys(49)/Lys(120) deacetylase. Inhibition of HDAC6 blocks 14-3-3ζ interactions with two well described interacting partners, Bad and AS160, which triggers their dephosphorylation at Ser(112) and Thr(642), respectively. Expression of an acetylation-refractory K49R/K120R mutant of 14-3-3ζ rescues both the HDAC6 inhibitor-induced loss of interaction and Ser(112)/Thr(642) phosphorylation. Furthermore, expression of the K49R/K120R mutant of 14-3-3ζ inhibits the cytotoxicity of HDAC6 inhibition. These data demonstrate a novel role for HDAC6 in controlling 14-3-3ζ binding activity.
