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1.
Cell Biol Int ; 42(3): 273-280, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28762604

RESUMO

TMEFF2 is a type I transmembrane protein with two follistatin (FS) and one EGF-like domain over-expressed in prostate cancer; however its biological role in prostate cancer development and progression remains unclear, which may, at least in part, be explained by its proteolytic processing. The extracellular part of TMEFF2 (TMEFF2-ECD) is cleaved by ADAM17 and the membrane-retained fragment is further processed by the gamma-secretase complex. TMEFF2 shedding is increased with cell crowding, a condition associated with the tumour microenvironment, which was mediated by oxidative stress signalling, requiring jun-kinase (JNK) activation. Moreover, we have identified that TMEFF2 is also a novel substrate for other proteases implicated in prostate cancer, including two ADAMs (ADAM9 and ADAM12) and the type II transmembrane serine proteinases (TTSPs) matriptase-1 and hepsin. Whereas cleavage by ADAM9 and ADAM12 generates previously identified TMEFF2-ECD, proteolytic processing by matriptase-1 and hepsin produced TMEFF2 fragments, composed of TMEFF2-ECD or FS and/or EGF-like domains as well as novel membrane retained fragments. Differential TMEFF2 processing from a single transmembrane protein may be a general mechanism to modulate transmembrane protein levels and domains, dependent on the repertoire of ADAMs or TTSPs expressed by the target cell.


Assuntos
Proteínas ADAM/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Estresse Oxidativo/fisiologia , Neoplasias da Próstata/metabolismo , Proteína ADAM12/metabolismo , Proteína ADAM17/metabolismo , Sequência de Aminoácidos , Membrana Celular/metabolismo , Células HEK293 , Humanos , Masculino , Neoplasias da Próstata/enzimologia , Neoplasias da Próstata/patologia , Espécies Reativas de Oxigênio/metabolismo , Serina Endopeptidases/metabolismo
2.
Biol Trace Elem Res ; 200(12): 5052-5063, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35061144

RESUMO

This study was aimed to explore the effect of astaxanthin (ASTX) and copper (Cu) supplementation on the growth, immunity, antioxidant, and blood biochemical status of growing Murrah buffalo heifers. Twenty-eight Murrah buffalo heifers were selected and randomly divided into 4 groups (n = 7) after blocking by body weight (BW) (129.86 ± 5.37 kg) and age (9.05 ± 1.02 months). The heifers were fed basal total mixed ration diet without supplementation (CON) or with ASTX (0.20 mg/kg BW; AX), Cu (10 mg/kg DM; CU), or ASTX + Cu (0.20 mg/kg BW + 10 mg/kg DM; AX + CU) for 90 days of study period. The result showed that BW and dry matter intake (DMI) were significantly higher (P < 0.05) in AX + CU than that in other groups. The average daily gain (ADG) and feed conversion efficiency (FCE) were statistically higher (P < 0.05) in treatments than the values observed in CON. The feed conversion ratio (FCR) was reported significantly lower (P < 0.05) in the AX + CU group followed by AX, CU, and CON groups. The total leukocytes count (TLC), lymphocytes, and total immunoglobulin (TIG) were statistically higher (P < 0.05) in AX + CU groups than that found in other groups. However, neutrophil % decreased (P < 0.05) in the AX + CU group than its level in other groups. Superoxide dismutase (SOD), catalase (CAT), and total antioxidant (TAA) levels were observed higher (P < 0.05) in treatments supplemented with ASTX, Cu, or both than CON group. Thiobarbituric acid reactive substance (TBARS) concentration was lower (P < 0.05) in treatments than its level found in the CON group. Glucose level was higher (P < 0.05); however, non-esterifies fatty acid (NEFA) was lower (P < 0.05) in AX + CU than that in others groups. The level of cholesterol (CH), HDL cholesterol (HDL-CH), alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) were reported lower (P < 0.05) in the AX + CU group followed by CU, AX, and CON groups. The copper (Cu) level was higher (P < 0.05) in CU and AX + CU than AX and CON groups. The result of the present study indicated that the supplementation of ASTX, Cu alone, or their combination improved the growth, immunity, antioxidant status, and liver function of growing heifers.


Assuntos
Antioxidantes , Búfalos , Alanina Transaminase , Fosfatase Alcalina , Ração Animal/análise , Animais , Antioxidantes/metabolismo , Aspartato Aminotransferases , Peso Corporal , Catalase , Bovinos , HDL-Colesterol , Cobre/metabolismo , Cobre/farmacologia , Dieta/veterinária , Suplementos Nutricionais , Ácidos Graxos não Esterificados , Feminino , Glucose , Imunoglobulinas , Superóxido Dismutase , Substâncias Reativas com Ácido Tiobarbitúrico , Xantofilas
3.
Hum Behav Emerg Technol ; 3(5): 1050-1066, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34901770

RESUMO

COVID-19 pandemic has affected every sphere of life specially the education sector observing a paradigm shift in the nature of pedagogy from offline face-to-face to online-virtual mode of learning. The biggest challenge in online-learning was the conduction of online examination for student's assessment specially in Indian context where digital divide is rampant. Thus, present study examines and compares the challenges faced by the students in two most widely accepted modes of examination by Indian universities and institutes of higher learning, that is, take home/unrestricted/assignment-based examination (ABE) and highly time restricted/open-book examination (OBE). Primary data was collected through questionnaires prepared by using Google forms to measure adaptability, satisfaction, and challenges using 5-point Likert's scale. Cronbach's α test was performed on question items to check the reliability and internal consistency of the items. χ 2 test has been applied in order to check whether there is a statistically significant relationship between the gender and place of residence in the acceptability of ABE and OBE. The findings suggest that both modes of examination have their own challenges largely governed by the digital and economic divide. The acceptance level of ABE and OBE is not associated with gender. However, we found the level of acceptance association of ABE with the place of residence of the students but not with OBE.

4.
Curr Biol ; 23(6): 453-61, 2013 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-23477725

RESUMO

BACKGROUND: Sorting ubiquitinated epidermal growth factor receptor (EGFR) to the intralumenal vesicles of the multivesicular body requires the coordinated action of several ESCRT complexes. A central question is how EGFR transits vectorially from early, ubiquitin-binding ESCRTs to the final complex, ESCRT-III, such that cargo sequestration is coupled with intralumenal vesicle formation. RESULTS: We show that the ESCRT accessory protein HD-PTP/PTPN23 associates with EGFR and combines with the deubiquitinating enzyme UBPY/USP8 to transfer EGFR from ESCRT-0 to ESCRT-III and drive EGFR sorting to intralumenal vesicles. HD-PTP binds ESCRT-0 via two interactions with the STAM2 subunit. First, the HD-PTP Bro1 domain binds the core domain of STAM2. This is competed by the ESCRT-III subunit CHMP4B, which binds an overlapping site on HD-PTP Bro1. Second, a proline-rich peptide in HD-PTP binds the SH3 domain of STAM2. Similar proline-rich peptides on UBPY also bind STAM2 SH3 to facilitate EGFR deubiquitination. Hence, locally recruited UBPY would be expected to compete with HD-PTP for STAM2 binding at this second site. Indeed, we show that HD-PTP recruits UBPY to EGFR. Association of UBPY with HD-PTP involves UBPY interacting with HD-PTP-bound CHMP4B, as well as additional interaction(s) between UBPY and HD-PTP. CONCLUSIONS: This study identifies HD-PTP as a central coordinator of the ESCRT pathway for EGFR. Based on these studies, we propose a model whereby the concerted recruitment of CHMP4B and UBPY to HD-PTP and the engagement of UBPY by STAM2 displaces ESCRT-0 from HD-PTP, deubiquitinates EGFR, and releases ESCRT-0 from cargo in favor of ESCRT-III.


Assuntos
Endopeptidases/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Receptores ErbB/metabolismo , Corpos Multivesiculares/metabolismo , Transporte Proteico , Proteínas Tirosina Fosfatases não Receptoras/metabolismo , Ubiquitina Tiolesterase/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Animais , Tomografia com Microscopia Eletrônica , Imunofluorescência , Células HeLa , Humanos , Camundongos , Saccharomyces cerevisiae , Técnicas do Sistema de Duplo-Híbrido
5.
J Biol Chem ; 282(52): 37378-88, 2007 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-17942404

RESUMO

The transmembrane protein with epidermal growth factor and two follistatin motifs 2 (TMEFF2) is expressed in prostate and brain and shed from the cell surface in a metalloproteinase-dependent fashion. Neither the sheddase(s) responsible for TMEFF2 shedding nor the physiological significance or activity of the soluble TMEFF2 ectodomain (TMEFF2-ECD) has been identified. In the present study we present new evidence that a disintegrin and metalloproteinase-17 (ADAM17) is responsible for phorbol 12-myristate 13-acetate-induced release of TMEFF2-ECD using small interfering RNA to ablate ADAM17 expression or by inhibiting enzymatic activity. A single well shedding assay monitoring the release of alkaline phosphatase-tagged TMEFF2-ECD into medium and the generation of 22- and 14-kDa C-terminal fragments in lysates were dependent on ADAM17 activity. A gamma-secretase inhibitor prevented the formation of a 10-kDa fragment in cell lysates, thus establishing TMEFF2 as a novel substrate for regulated intramembrane proteolysis. We assigned proliferation-inducing activity to TMEFF2. Inhibition of TMEFF2 shedding using synthetic metalloproteinase inhibitors or small interfering RNA targeting TMEFF2 expression yielded a statistically significant reduction of cell proliferation in the lymph node-derived prostate cancer cells (LNCaPs) and a human embryonic kidney (HEK293) cell line overexpressing TMEFF2. The TMEFF2-ECD was able to induce ERK1/2 phosphorylation in an epidermal growth factor receptor (or ErbB1)-dependent manner in HEK293 cells. Our data suggest that TMEFF2 contributes to cell proliferation in an ADAM17-dependent autocrine fashion in cells expressing this protein.


Assuntos
Proteínas ADAM/química , Membrana Celular/metabolismo , Fator de Crescimento Epidérmico/metabolismo , Folistatina/química , Proteínas de Membrana/metabolismo , Proteínas de Neoplasias/metabolismo , Ésteres de Forbol/farmacologia , Neoplasias da Próstata/metabolismo , Proteína ADAM17 , Motivos de Aminoácidos , Linhagem Celular , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Masculino , Modelos Biológicos , Conformação Proteica , Estrutura Terciária de Proteína , RNA Interferente Pequeno/metabolismo
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