2,958 research outputs found

    Sorting of lysosomal proteins

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    AbstractLysosomes are composed of soluble and transmembrane proteins that are targeted to lysosomes in a signal-dependent manner. The majority of soluble acid hydrolases are modified with mannose 6-phosphate (M6P) residues, allowing their recognition by M6P receptors in the Golgi complex and ensuing transport to the endosomal/lysosomal system. Other soluble enzymes and non-enzymatic proteins are transported to lysosomes in an M6P-independent manner mediated by alternative receptors such as the lysosomal integral membrane protein LIMP-2 or sortilin. Sorting of cargo receptors and lysosomal transmembrane proteins requires sorting signals present in their cytosolic domains. These signals include dileucine-based motifs, DXXLL or [DE]XXXL[LI], and tyrosine-based motifs, YXXØ, which interact with components of clathrin coats such as GGAs or adaptor protein complexes. In addition, phosphorylation and lipid modifications regulate signal recognition and trafficking of lysosomal membrane proteins. The complex interaction of both luminal and cytosolic signals with recognition proteins guarantees the specific and directed transport of proteins to lysosomes

    Clinical-pathological features of an occult mixed mucinous male breast cancer. a case report

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    Mucinous carcinoma of the male breast is an uncommon malignant breast neoplasm and its diagnoses remain difficult. It is probably due to such a low rate of breast cancer cases that men tend to be diagnosed at an older age than women and with a later stage of the disease. We describe a case of a 69-year-old male who displayed a palpable lump in his right axilla several years ago, showing signs of cutaneous adnexal mucinous adenocarcinoma after biopsy. After six years and several clinical examination and systemic investigation without results, the patient underwent to fine needle aspiration cytology and subsequently a biopsy of a mass with irregular margins in the retroareolar region of his right breast. The final diagnosis was of a mixed mucinous breast cancer with neuroendocrine differentiation. The tumor cells phenotype showed Synaptophisin (+), CEA (+/-), CK-20 (-), CK-7 (+), TTF-1 (-), estrogen receptor (-), progesterone (-) and HER 2 (++). These results were unusual for a mucinous male breast carcinoma. In the presence of a lesion in the axillary area with no specific primary origin, breast cancer should never be ruled out, even in the absence of clinical evidence and with an immunohistochemical pattern not indicative of mammary origin

    The Mechanisms of Vesicle Budding and Fusion

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    AbstractGenetic and biochemical analyses of the secretory pathway have produced a detailed picture of the molecular mechanisms involved in selective cargo transport between organelles. This transport occurs by means of vesicular intermediates that bud from a donor compartment and fuse with an acceptor compartment. Vesicle budding and cargo selection are mediated by protein coats, while vesicle targeting and fusion depend on a machinery that includes the SNARE proteins. Precise regulation of these two aspects of vesicular transport ensures efficient cargo transfer while preserving organelle identity

    The genus Panphalea (Compositae: Nassauvieae) in Uruguay

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    Se realiza la revisión taxonómica de Panphalea Lag. (Compositae: Nassauvieae) para Uruguay. Panphalea en Uruguay consiste de cinco especies: Panphalea bupleurifolia Less., Panphalea cardaminifolia Less., Panphalea commersonii Cass., Panphalea heterophylla Less. y Panphalea maxima Less. Todas las especies uruguayas fueron evaluadas y circunscriptas en base al análisis de los protólogos, análisis de laboratorio, estudio cuidadoso del material tipo, observación de especímenes de herbario y observaciones a campo. Se presenta una clave dicotómica para la identificación de las especies reconocidas para el Uruguay. Para cada especie se provee sinonimia, descripciones ampliadas, distribución geográfica y dibujos. Se designan dos neotipos.A taxonomic revision of Panphalea Lag. (Compositae: Nassauvieae) for Uruguay is presented. Panphalea, in Uruguay, is composed of five species: Panphalea bupleurifolia Less., Panphalea cardaminifolia Less., Panphalea commersonii Cass., Panphalea heterophylla Less., and Panphalea maxima Less. All uruguayan species of Panphalea were taxonomically evaluated and circumscribed based on analyses of the protologues, laboratory studies, and careful study of type material, herbarium specimens and field observations. A dichotomous key for the identification of the Uruguayan species is provided. For each species, synonymy, detailed description, geographic distribution, and line drawings are presented. Two neotypes are designated.Fil: Trujillo, Cristina. Universidad de la República; UruguayFil: Katinas, Liliana. Universidad Nacional de la Plata. Facultad de Ciencias Naturales y Museo. División de Plantas Vasculares; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Bonifacino, José M.. Universidad de la República; Urugua

    Trichocline maxima (Compositae, Mutisieae) a rare Pampean daisy rediscovered after 70 years in Uruguay

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    Trichocline maxima was considered probably extinct but has been rediscovered in northern Uruguay after almost 70 years since its last record in this country. We provide an updated description of the species, an indication of a lectotype and we discuss morphology, taxonomy, nomenclature, geographical distribution, and conservation status of the species. An identification key for the species of the genus in Uruguay and Brazil is also presented.Trichocline maxima (Compositae, Mutisieae) redescoberta: Taxonomia, lectotipificação, e estado de conservação de uma Asteraceae rara e endêmica do Pampa. Trichocline maxima era considerada como provavelmente extinta, mas foi redescoberta no norte do Uruguai após quase 70 anos desde sua última coleta neste país. Neste trabalho são fornecidas descrição atualizada da espécie, a indicação de um lectótipo e discussão sobre aspectos morfológicos, taxonômicos, nomenclaturais, de distribuição geográfica e estado de conservação. Também é presentada uma chave de identificação para as espécies do gênero no Uruguai e no Brasil
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