RESUMO
RAS GTPases bind effectors to convert upstream cues to changes in cellular function. Effectors of classical H/K/NRAS are defined by RBD/RA domains which recognize the GTP-bound conformation of these GTPases, yet the specificity of RBD/RAs for over 160 RAS superfamily proteins remains poorly explored. We have systematically mapped interactions between BRAF and four RASSF effectors, the largest family of RA-containing proteins, with all RAS, RHO and ARF small GTPases. 39 validated complexes reveal plasticity in RASSF binding, while BRAF demonstrates tight specificity for classical H/K/NRAS. Complex between RASSF5 and diverse RAS GTPases at the plasma membrane can activate Hippo signalling and sequester YAP in the cytosol. RASSF8 undergoes liquid-liquid phase separation and resides in YAP-associated membraneless condensates, which also engage several RAS and RHO GTPases. The poorly studied RASSF3 has been identified as a first potential effector of mitochondrial MIRO proteins, and its co-expression with these GTPases impacts mitochondria and peroxisome distribution. These data reveal the complex nature of GTPase-effector interactions and show their systematic elucidation can reveal completely novel and biologically relevant cellular processes.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Ligação Proteica , Proteínas ras , Humanos , Proteínas ras/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de Sinalização YAP/metabolismo , Transdução de Sinais , Proteínas Supressoras de Tumor/metabolismo , Proteínas Supressoras de Tumor/genética , Mitocôndrias/metabolismo , Células HEK293 , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas Reguladoras de Apoptose/genética , Transporte Proteico , Membrana Celular/metabolismoRESUMO
Thousand-and-one-amino acid kinase 3 (TAOK3) is a serine and threonine kinase that belongs to the STE-20 family of kinases. Its absence reduces T cell receptor (TCR) signaling and increases the interaction of the tyrosine phosphatase SHP-1, a major negative regulator of proximal TCR signaling, with the kinase LCK, a component of the core TCR signaling complex. Here, we used mouse models and human cell lines to investigate the mechanism by which TAOK3 limits the interaction of SHP-1 with LCK. The loss of TAOK3 decreased the survival of naïve CD4+ T cells by dampening the transmission of tonic and ligand-dependent TCR signaling. In mouse T cells, Taok3 promoted the secretion of interleukin-2 (IL-2) in response to TCR activation in a manner that depended on Taok3 gene dosage and on Taok3 kinase activity. TCR desensitization in Taok3-/- T cells was caused by an increased abundance of Shp-1, and pharmacological inhibition of Shp-1 rescued the activation potential of these T cells. TAOK3 phosphorylated threonine-394 in the phosphatase domain of SHP-1, which promoted its ubiquitylation and proteasomal degradation. The loss of TAOK3 had no effect on the abundance of SHP-2, which lacks a residue corresponding to SHP-1 threonine-394. Modulation of SHP-1 abundance by TAOK3 thus serves as a rheostat for TCR signaling and determines the activation threshold of T lymphocytes.
Assuntos
Proteínas Serina-Treonina Quinases , Receptores de Antígenos de Linfócitos T , Linfócitos T , Animais , Humanos , Camundongos , Proteína Tirosina Quinase p56(lck) Linfócito-Específica , Fosforilação , Proteínas Serina-Treonina Quinases/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 11/genética , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Proteína Tirosina Fosfatase não Receptora Tipo 6/genética , Proteína Tirosina Fosfatase não Receptora Tipo 6/metabolismo , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/metabolismo , Linfócitos T/metabolismo , Treonina/metabolismoRESUMO
Introducción: La adherencia al tratamiento farmacológico favorece la supresión viral y reduce la resistencia a la terapia antirretroviral de gran actividad a largo plazo. Objetivo: Determinar la relación entre los aspectos farmacológicos y la adherencia al tratamiento antirretroviral de una IPS colombiana. Metodología: Estudio analítico transversal en pacientes con diagnóstico de VIH en tratamiento antirretroviral entre los años 2012 a 2020. Se utilizó un modelo de regresión logística binaria múltiple con fines explicativos. Resultados: Se analizaron 9835 pacientes donde la proporción de adherencia fue de 90 % y en el modelo ajustado se evaluó su relación con los antecedentes de no adherencia (ORa:0,52 IC95 °/o:0,40-0,66), grupo farmacológico (2 ITIAN + 1 IP u otro) (ORa:1,22 IC95 %:0,99-1,76), dos tomas al día (ORa:1,02 IC95 %:0,74-1,40), unidades al día (≥ 3) (ORa:0,69 IC95 %:0,47-1,02), reacciones adversas a medicamentos (ORa:0,56 IC95 °%:0,40-0,78), polimedicación (ORa:1,36 IC95 %:1,00-1,85), tiempo TAR (1 a 2 años) (ORa:1,63 IC95 %:1,27-2,09),tiempo TAR (6 a 12 meses) (ORa:1,66 IC95 %:1,27-2,18), tiempo TAR (<6 meses) (ORa:1,36 IC95 %:1,03-1,78), tasa de reclamación de los medicamentos (ORa:0,42 IC95 %:0,32-0,55) y antecedentes PRUM (ORa:0,11 IC95 %:0,09-0,14). Discusión: La proporción de adherencia obtenida es superior a lo descrito para otros países (entre 60-77 %); sin embargo se encuentra que los hallazgos correspondientes al efecto de las variables farmacológicas analizadas son acordes a lo descrito en estudios previos en el tema Conclusión: Los antecedentes de no adherencia, reacciones adversas, tasa de reclamación de los medicamentos y antecedentes de problemas relacionados con el uso de medicamentos son aspectos que reducen la probabilidad de adherencia; mientras que el mayor tiempo de uso del tratamiento aumenta la misma.
Introduction: Adherence to drug treatment promotes viral suppression and reduces long-term resistance to highly active antiretroviral therapy (HAART). Objective: To determine the relationship between the pharmacological aspects and adherence to antiretroviral treatment in a Colombian IPS. Methodology: Cross-sectional analytical study in patients with HIV on antiretroviral treatment between 2012 and 2020. A multiple binary logistic regression model was used for explanatory purposes. Results: A total of 9,835 patients were analyzed where the proportion of adherence was 90 % and in the adjusted model its relationship with history of non-adherence was assessed (ORa: 0,52 95 % CI: 0,40-0,66), pharmacological group (2 NRTI + 1 PI or other) (ORa: 1,22 95 % CI: 0,99-1,76), two doses per day (ORa: 1,02 95 % CI: 0,74-1,40), units per day (≥ 3 ) (ORa: 0,69 95 % CI: 0,47-1,02), adverse drug reactions (ORa: 0,56 95 % CI: 0,40-0,78), polypharmacy (ORa: 1,36 95 % CI : 1,00-1,85), ART time (1 to 2 years) (ORa: 1,63 95 % CI: 1,27-2,09), ART time (6 to 12 months) (ORa: 1,66 95 % CI: 1,27-2,18), ART time (<6 months) (ORa: 1,36 95 % CI: 1,03-1,78), inconsistency in the claim (ORa: 0,42 95 % CI: 0,32-0,55) and PRUM history (ORa: 0,11 95 % CI: 0,09-0,14). Discussion: The proportion of adherence obtained is higher than that described for other countries (between 60-77 %); however, the findings corresponding to the effect of the pharmacological variables analysed are in line with those described in previous studies on the subject. Conclusion: The history of non-adherence, adverse reactions, inconsistencies in the claim fill history and problems related to the use of medications are aspects that reduce the probability of adherence. While the longer time of use of the treatment increases adherence.