Disease relevance of Rab1

• In a genomewide screen, the largest class of toxicity modifiers were proteins functioning at this same step, including the Rab guanosine triphosphatase Ypt1p, which associated with cytoplasmic alphaSyn inclusions [1].

High impact information on Rab1

• To investigate the molecular mechanisms responsible for the organization of membrane compartments, we identified members of the SNARE, coat complex, Rab and Sec1 protein families in four eukaryotic genomes [2].
• The pattern of telomeric associations observed in UbcD1 mutants suggests strongly that the interphase chromosomes of wild-type larval brain cells maintain a Rab1 orientation within the nucleus, with the telomeres and centromeres segregated to opposite sides of the nucleus [3].
• Here we report that mutations in two core components of the vesicle trafficking machinery - a syntaxin and a Rab protein - cause an expansion of the apical membrane domain of Drosophila melanogaster epithelia; this polarity defect is coupled with overproliferation to form neoplastic tumours [4].
• We have utilized short-term expression of dominant negative Rab proteins to examine the polarity of endocytic trafficking of Wingless and its receptors and to determine the relative contributions of endocytosis, degradation and recycling to the establishment of the Wingless gradient [5].
• In situ inhibition of vesicle transport and protein processing in the dominant negative Rab1 mutant of Drosophila [6].

Biological context of Rab1

• To investigate the role of RAB1 in developing or functioning cells in situ, we constructed transgenic, dominant-negative Rab1 mutants of Drosophila, and examined the protein transport and cellular and subcellular structures of mutant photoreceptor cells [6].
• Using mRNA in situ hybridisation, we show here that ecdysone triggers the upregulation of a subset of genes encoding Golgi-related proteins (such as dnsf1, dsec23, dsed5, and drab1) and downregulates the expression of others (such as dergic53, dbeta'COP, and drab6) [7].
• From a Drosophila head cDNA library, we isolated 9 cDNA clones, each of which encodes a different member of Rab-protein family [8].
• This result suggests that Rab protein in the brain of Bombyx mori binds GDP or GTP and its function is regulated by phosphorylation [9].
• The amino-acid sequence deduced from the longer cDNA indicated that the C-terminal 1/3 of the sequence shares homology with Rab proteins, whereas the rest of the peptide shows no significant homology with any other proteins [10].

Other interactions of Rab1

• The other two proteins (DRabRP3 and 4) show low sequence similarity to any of the known Rab proteins [8].
• Here, we describe the unique characteristics of a novel Rab protein, RABRP1 (Rab-Related Protein 1) [10].

Analytical, diagnostic and therapeutic context of Rab1

• Elevated expression of Rab1, the mammalian YPT1 homolog, protected against alphaSyn-induced dopaminergic neuron loss in animal models of PD [1].

References