Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A cosmid clone containing the complete coding sequence of the human properdin gene has been characterized. The gene is located at one end of the approximately 40 kb cosmid insert and approximately 8.2 kb of the sequence data have been obtained from this region. Two discrepancies with the published cDNA sequence [Nolan, Schwaeble, Kaluz, Dierich & Reid (1991) Eur. J. Immunol. 21, 771-776] have been resolved. Properdin has previously been described as a modular protein, with the majority of its sequence composed of six tandem repeats of a sequence motif of approximately 60 amino acids which is related to the type-I repeat sequence (TSR), initially described in thrombospondin [Lawler & Hynes (1986) J. Cell Biol. 103, 1635-1648; Goundis & Reid (1988), Nature (London) 335, 82-85]. Analysis of the genomic sequence data indicates that the human properdin gene is organized into ten exons which span approximately 6 kb of the genome. TSRs 2-5 are coded for by discrete, symmetrical exons (phase 1-1), which supports the hypothesis that modular proteins evolved by a process involving exon shuffling. TSR1 is also coded for by a discrete exon, but the boundaries are asymmetrical (phase 2-1). The sequence coding for the sixth TSR is split across the final two exons of the gene with the first 38 amino acids of the repeat coded for by an asymmetric exon (phase 1-2). This split at the genomic level has been shown, by alignment analysis, to be reflected at the protein level with the division of repeat 6 into TSR-like and TSR-unlike sequences.
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PMID:Characterization of the human properdin gene. 141 80

Astroglia play key roles in the development of neurons, ranging from regulating neuron survival to promoting synapse formation, yet basic questions remain about whether astrocytes might be involved in forming the dendritic arbor. Here, we used cultured hippocampal neurons as a simple in vitro model that allowed dendritic growth and geometry to be analyzed quantitatively under conditions where the extent of interactions between neurons and astrocytes varied. When astroglia were proximal to neurons, dendrites and dendritic filopodia oriented toward them, but the general presence of astroglia significantly reduced overall dendrite growth. Further, dendritic arbors in partial physical contact with astroglia developed a pronounced pattern of asymmetrical growth, because the dendrites in direct contact were significantly smaller than the portion of the arbor not in contact. Notably, thrombospondin, the astroglial factor shown previously to promote synapse formation, did not inhibit dendritic growth. Thus, while astroglia promoted the formation of presynaptic contacts onto dendrites, dendritic growth was constrained locally within a developing arbor at sites where dendrites contacted astroglia. Taken together, these observations reveal influences on spatial orientation of growth as well as influences on morphogenesis of the dendritic arbor that have not been previously identified.
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PMID:Interactions with Astroglia Influence the Shape of the Developing Dendritic Arbor and Restrict Dendrite Growth Independent of Promoting Synaptic Contacts. 2808 63