PMID- 10212200
OWN - NLM
STAT- MEDLINE
DCOM- 19990603
LR  - 20210209
IS  - 0021-9258 (Print)
IS  - 0021-9258 (Linking)
VI  - 274
IP  - 18
DP  - 1999 Apr 30
TI  - Purification and cloning of a brefeldin A-inhibited guanine nucleotide-exchange
      protein for ADP-ribosylation factors.
PG  - 12308-15
AB  - Activation of ADP-ribosylation factors (ARFs), approximately 20-kDa guanine
      nucleotide-binding proteins that play an important role in intracellular
      vesicular trafficking, depends on guanine nucleotide-exchange proteins (GEPs),
      which accelerate replacement of bound GDP with GTP. Two major families of ARF
      GEPs are known: approximately 200-kDa molecules that are inhibited by brefeldin A
      (BFA), a fungal metabolite that blocks protein secretion and causes apparent
      disintegration of Golgi structure, and approximately 50-kDa GEPs that are
      insensitive to BFA. We describe here two human brain cDNAs that encode
      BFA-inhibited GEPs. One is a approximately 209-kDa protein 99.5% identical in
      deduced amino acid sequence (1, 849 residues) to a BFA-inhibited ARF GEP (p200)
      from bovine brain. The other smaller protein, which is approximately 74%
      identical (1, 785 amino acids), represents a previously unknown gene. We propose 
      that the former, p200, be named BIG1 for (brefeldin A-inhibited GEP1) and the
      second, which encodes a approximately 202-kDa protein, BIG2. A protein containing
      sequences found in BIG2 had been purified earlier from bovine brain. Human
      tissues contained a 7.5-kilobase BIG1 mRNA and a 9.4-kilobase BIG2 transcript.
      The BIG1 and BIG2 genes were localized, respectively, to chromosomes 8 and 20.
      BIG2, synthesized as a His6 fusion protein in Sf9 cells, accelerated guanosine
      5'-3-O-(thio)triphosphate binding by recombinant ARF1, ARF5, and ARF6. It
      activated native ARF (mixture of ARF1 and ARF3) more effectively than it did any 
      of the nonmyristoylated recombinant ARFs. BIG2 activity was inhibited by BFA in a
      concentration-dependent manner but not by B17, a structural analog without
      effects on Golgi function. Although several clones for approximately 50-kDa
      BFA-insensitive ARF GEPs are known, these new clones for the approximately
      200-kDa BIG1 and BIG2 should facilitate characterization of this rather different
      family of proteins as well as the elucidation of mechanisms of regulation of
      BFA-sensitive ARF function in Golgi transport.
FAU - Togawa, A
AU  - Togawa A
AD  - Pulmonary-Critical Care Medicine Branch, NHLBI, National Institutes of Health,
      Bethesda, Maryland 20892, USA. togawaa@gwgate.nhlbi.nih.gov
FAU - Morinaga, N
AU  - Morinaga N
FAU - Ogasawara, M
AU  - Ogasawara M
FAU - Moss, J
AU  - Moss J
FAU - Vaughan, M
AU  - Vaughan M
LA  - eng
SI  - GENBANK/AF084520
SI  - GENBANK/AF084521
PT  - Journal Article
PL  - United States
TA  - J Biol Chem
JT  - The Journal of biological chemistry
JID - 2985121R
RN  - 0 (ARFGEF1 protein, human)
RN  - 0 (ARFGEF2 protein, human)
RN  - 0 (DNA, Complementary)
RN  - 0 (Guanine Nucleotide Exchange Factors)
RN  - 0 (Recombinant Proteins)
RN  - 20350-15-6 (Brefeldin A)
RN  - EC 3.6.1.- (GTP-Binding Proteins)
RN  - EC 3.6.5.2 (ADP-Ribosylation Factor 1)
RN  - EC 3.6.5.2 (ADP-Ribosylation Factors)
SB  - IM
MH  - ADP-Ribosylation Factor 1
MH  - ADP-Ribosylation Factors
MH  - Amino Acid Sequence
MH  - Animals
MH  - Base Sequence
MH  - Brefeldin A/*pharmacology
MH  - Cattle
MH  - Cloning, Molecular
MH  - DNA, Complementary
MH  - GTP-Binding Proteins/genetics/*isolation & purification/*metabolism
MH  - *Guanine Nucleotide Exchange Factors
MH  - Humans
MH  - Molecular Sequence Data
MH  - Recombinant Proteins/genetics/isolation & purification/metabolism
MH  - Sequence Homology, Amino Acid
EDAT- 1999/04/23 00:00
MHDA- 1999/04/23 00:01
CRDT- 1999/04/23 00:00
PHST- 1999/04/23 00:00 [pubmed]
PHST- 1999/04/23 00:01 [medline]
PHST- 1999/04/23 00:00 [entrez]
AID - 10.1074/jbc.274.18.12308 [doi]
AID - S0021-9258(19)73355-9 [pii]
PST - ppublish
SO  - J Biol Chem. 1999 Apr 30;274(18):12308-15. doi: 10.1074/jbc.274.18.12308.