RESUMO
The nuclear matrix in eukaryotes is a non-histone proteinaceous nucleoskeleton structure having attachment sites for DNA loops during DNA replication. The nuclear matrix has been implicated in transcription, regulation of gene expression, primary transcription processing and provides a mooring for certain hormone receptors. Moreover, the nuclear matrix protein has linkages to intermediate filaments of the cytoskeleton. This review presents recent advances concerning the involvement of the nuclear matrix in DNA replication, relaxation of the superhelical strain in DNA, processing of hnRNA and snRNP, and RNA transport.
Assuntos
Matriz Nuclear/fisiologia , Animais , Antígenos Nucleares , Proteínas do Citoesqueleto/metabolismo , DNA/metabolismo , Replicação do DNA , Expressão Gênica , Humanos , Matriz Nuclear/enzimologia , Proteínas Nucleares/metabolismo , Fosforilação , RNA/metabolismo , Ribonucleoproteínas Nucleares Pequenas/metabolismo , Proteínas Virais/metabolismoRESUMO
Cerebrospinal fluid (CSF) from twenty three patients with non specific mental retardation and fourteen age matched normal samples was subjected for qualitative analysis of protein profiles by two-dimensional gel electrophoresis (2-DE) and the proteins were visualised by ultra sensitive silver staining. Two proteins designated as mental retardation associated proteins (MRAP-I and MRAP-II) were identified in six male patients out of twenty three patients CSF samples. MRAP-I had an isoelectric point of 7.4 with a relative molecular weight 16.5 kDa, while MRAP-II had an iso-electric point of 7.2 with a relative molecular weight 16.8 kDa. The two proteins are presumed to be originated from brain, as they could not be traced in the serum of patients, nor due to proteolytic degradation. Despite unknown origin and identity, their presence in the CSF of a specific group of mentally retarded male patients suggest their possible clinical utility and to define protein alterations in mental retardation.
