The ras-like protein p25rab3A is partially cytosolic and is expressed only in neural tissue.

Burstein, Ethan S.; Macara, Ian G.

doi:10.1128/mcb.9.11.4807

Cited by 41 publications

(22 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Effector domain peptides have, in fact, been shown to inhibit transport in the biosynthetic pathway (Plutner et al, 1990). Proteins have been identified that can escort rab proteins in the cytosol (GDI), stimulate GTP hydrolysis or facilitate GDP/GTP exchange (Huang et al, 1990;Sasaki et al, 1990;West et al, 1990;Burstein et al, 1991;Tan et al, 1991;Burstein and Macara, 1992). Other proteins, which include putative components of the transport machinery, are expected to interact with rab proteins.…”

Section: Introductionmentioning

confidence: 99%

The N-terminal domain of a rab protein is involved in membrane-membrane recognition and/or fusion.

et al. 1994

View full text Add to dashboard Cite

Proteins of the YPT1/SEC4/rab family are well documented to be involved in the regulation of membrane transport. We have previously reported that rab5 regulates endosome-endosome recognition and/or fusion in vitro. Here, we show that this process depends on the rab5 N-terminal domain. Treatment of early endosomal membranes at a low trypsin concentration essentially abolished fusion and cleaved rab5 to a 1 kDa smaller polypeptide. Two-dimensional gel analysis suggested that rab5 is one of the few, if not the only, polypeptides cleaved by trypsin under these conditions. Whereas endosome fusion could be stimulated by cytosol prepared from cells overexpressing rab5 (and thus containing high amounts of the protein), this stimulation was abolished by trypsin-treatment of the cytosol. Trypsin-treated cytosol prepared from mock-transfected cells, which contains very low amounts of rab5, showed no inhibitory activity indicating that rab5 is the target of trypsin in these experiments. Purified rab5 prepared after expression in Escherichia coli was treated with trypsin, which cleaved the protein at the N-terminus. A synthetic peptide of rab5 N-terminal domain inhibited endosome fusion in our cell-free assay. A version of the same peptide truncated at the N-terminus or a peptide of rab3 N-terminal domain were without effects. Altogether, these observations suggest that the N-terminal domain of rab5 is involved in the process of early endosome recognition and/or fusion, presumably because it interacts with another component of the transport machinery.

show abstract

Section: Introductionmentioning

confidence: 99%

The N-terminal domain of a rab protein is involved in membrane-membrane recognition and/or fusion.

et al. 1994

View full text Add to dashboard Cite

show abstract

“…Therefore, rab proteins could also be involved in intracellular traffic. With the exception of rab3p, which seems to be only present in nervous and endocrine cells (7)(8)(9)(10)(11)(12), rab lAp, 2p, 4p, 5p, and 6p appear to be ubiquitously distributed (6,7). Mature phagocytes are involved in different functions such as degranulation, phagolysosome formation, and directed locomotion that require organized intracellular traffic and sorting of granules and vesicles (1 3, 14).…”

Section: Introductionmentioning

confidence: 99%

Increase in the expression of a family of small guanosine triphosphate-binding proteins, rab proteins, during induced phagocyte differentiation.

Maridonneau‐Parini¹,

Yang²,

Bornens³

et al. 1991

J. Clin. Invest.

View full text Add to dashboard Cite

Rab is a newly identified family of small G-proteins that share 35-70% homology with the yeast Sec4p and Yptlp involved in the regulation of the secretory pathway. Mature phagocytes display functions requiring organized intracellular traffic and, for this reason, we questioned whether phagocyte differentiation could correlate with the increased expression of rab proteins. Rabbit antisera raised against the recombinant proteins rablAp, 2p, 4p, and 6p were able to detect the corresponding proteins in the human monoblast leukemic cell line U937. When these cells were induced to differentiate into monocyte/ macrophage-like cells displaying functional characteristics of a normal phagocyte, rablAp, 2p, 4p, and 6p were increased and this correlated with an increase in the rab transcripts. Using a rab5 probe, we also observed an increased expression of the rab5 gene in differentiated cells. Similarly, differentiation of the human leukemic myeloblast HL60 cell line along either monocyte or granulocyte pathways induced an increased expression of the rab proteins. Rab proteins were also detected in human neutrophils and in guinea pig alveolar macrophages. As degranulation is one of the phagocyte functions acquired in the late stage of differentiation, we investigated whether rab proteins would be involved in this process. Although rab proteins were tightly membrane bound, none of them was detected in the specific or azurophil granules purified from human neutrophils. The increased expression of rab proteins in mature phagocytes suggests that they may promote functions highly developed in these cells. (J. Clin. Invest. 1991. 87:901-907.)

show abstract

“…Rab3A GTPase is expressed predominantly in neuronal and chromaffin cells, where it is associated with the membranes of synaptic vesicles and chromaffin granules (8,13,25,31). Membrane attachment requires the posttranslational modification of the two C-terminal Cys residues of Rab3A by geranylgeranylation (15).…”

mentioning

confidence: 99%

Role of the Rab3A-Binding Domain in Targeting of Rabphilin-3A to Vesicle Membranes of PC12 Cells

McKiernan

Stabila

Macara

1996

Molecular and Cellular Biology

Self Cite

View full text Add to dashboard Cite

Rab3A is a small GTPase implicated in the docking of secretory vesicles in neuroendocrine cells. A putative downstream target for Rab3A, rabphilin-3A, is located exclusively on secretory vesicle membranes. It contains near its C terminus two C 2 domains that bind Ca 2؉ in a phospholipid-dependent manner and an N-terminal, Rab3A-binding domain that includes a Cys-rich region. We have determined that the Cys-rich domain binds two Zn 2؉ ions and is necessary but not sufficient for efficient binding of rabphilin to Rab3A. A minimal Rab3A-binding domain consists of residues 45 to 170 of rabphilin. HA1-tagged Rab3A and a green fluorescent protein (GFP)-rabphilin fusion were used to examine the roles of Rab3A and of rabphilin domains in the subcellular localization of these proteins. A Rab3A mutant (T54A) that does not bind rabphilin in vitro colocalized with the GFP-rabphilin fusion, indicating that Rab3A targeting is independent of its interaction with rabphilin. Deletion of the C 2 domains of rabphilin reduced membrane association of GFP-rabphilin but did not cause mistargeting of the membrane-associated fraction. However, disruption of the zinc fingers, which drastically reduced Rab3A binding, did not reduce membrane association. These results suggest that the C 2 domains are required for efficient membrane attachment of rabphilin in PC12 cells and that Rab3A binding may act to target the protein to the correct membrane.

show abstract

The ras-like protein p25rab3A is partially cytosolic and is expressed only in neural tissue.

Cited by 41 publications

References 24 publications

The N-terminal domain of a rab protein is involved in membrane-membrane recognition and/or fusion.

The N-terminal domain of a rab protein is involved in membrane-membrane recognition and/or fusion.

Increase in the expression of a family of small guanosine triphosphate-binding proteins, rab proteins, during induced phagocyte differentiation.

Role of the Rab3A-Binding Domain in Targeting of Rabphilin-3A to Vesicle Membranes of PC12 Cells

Contact Info

Product

Resources

About