Complex Patterns of Alternative Splicing Mediate the Spatial and Temporal Distribution of Perlecan/UNC-52 in Caenorhabditis elegans

The unc-52 gene encodes the nematode homologue of mammalian perlecan, the major heparan sulfate proteoglycan of the extracellular matrix. This is a large complex protein with regions similar to low-density lipoprotein receptors, laminin, and neural cell adhesion molecules (NCAMs). In this study, we extend our earlier work and demonstrate that a number of complex isoforms of this protein are expressed through alternative splicing. We identified three major classes of perlecan isoforms: a short form lacking the NCAM region and the C-terminal agrin-like region; a medium form containing the NCAM region, but still lacking the agrin-like region; and a newly identified long form that contains all five domains present in mammalian perlecan.  Using region-specific antibodies and unc-52 mutants, we reveal a complex spatial and temporal expression pattern for these UNC-52 isoforms. As well, using a series of mutations affecting different regions and thus different isoforms of UNC-52, we demonstrate that the medium NCAM-containing isoforms are sufficient for myofilament lattice assembly in developing nematode body-wall muscle. Neither short isoforms nor isoforms containing the C-terminal agrin-like region are essential for sarcomere assembly or muscle cell attachment, and their role in development remains unclear.

O Senado Federal e o controle concreto de constitucionalidade de leis e de atos normativos : separação de poderes, Poder Legislativo e interpretação da CF 52 X / Nelson Nery Junior.

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Constituição, artigo 52, inciso X : reversibilidade

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Modulação dos efeitos temporais no controle jurisdicional de constitucionalidade e reflexos sobre a norma do art. 52, X, da Constituição Federal

"Artigo produzido com base no trabalho de conclusão do Curso de Especialização em Análise e Controle de Constitucionalidade, promovido pela Unilegis - Universidade do Legislativo em parceria com a Universidade de Brasília - UnB, como requisito para a obtenção do título de Especialista. Orientador: Prof. Leonardo Augusto de Andrade Barbosa".