The p47 co‐factor regulates the ATPase activity of the membrane fusion protein, p97

Meyer, Hemmo; Kondo, Hisao; Warren, Graham

doi:10.1016/s0014-5793(98)01232-0

Cited by 98 publications

(97 citation statements)

References 25 publications

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“…p97(E305Q) was similar to wild-type p97 and hydrolyzed ATP at a rate comparable to that previously reported for p97/VCP (ϳ7 nmol/h/ g p97; Peters et al, 1992;Egerton and Samelson, 1994;Meyer et al, 1998), whereas p97(E578Q) had severely impaired ATPase activity. The double mutant p97(E305/578Q) had no ATPase activity.…”

Section: Inverse Arrangement Of Aaa Domains In Nsf and P97supporting

confidence: 86%

Distinct Roles for the AAA ATPases NSF and p97 in the Secretory Pathway

Dalal

Rosser

Cyr

et al. 2004

MBoC

165

174

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NSF and p97 are related AAA proteins implicated in membrane trafficking and organelle biogenesis. p97 is also involved in pathways that lead to ubiquitin-dependent proteolysis, including ER-associated degradation (ERAD). In this study, we have used dominant interfering ATP-hydrolysis deficient mutants (NSF(E329Q) and p97(E578Q)) to compare the function of these AAA proteins in the secretory pathway of mammalian cells. Expressing NSF(E329Q) promotes disassembly of Golgi stacks into dispersed vesicular structures. It also rapidly inhibits glycosaminoglycan sulfation, reflecting disruption of intra-Golgi transport. In contrast, expressing p97(E578Q) does not affect Golgi structure or function; glycosaminoglycans are normally sulfated and secreted, as is the VSV-G ts045 protein. Instead, expression of p97(E578Q) causes ubiquitinated proteins to accumulate on ER membranes and slows degradation of the ERAD substrate cystic-fibrosis transmembrane-conductance regulator. In addition, expression of p97(E578Q) eventually causes the ER to swell. More specific assessment of effects of p97(E578Q) on organelle assembly shows that the Golgi apparatus disperses and reassembles normally after treatment with brefeldin A and during mitosis. These findings demonstrate that ATPhydrolysis-dependent activities of NSF and p97 in the cell are not equivalent and suggest that only NSF is directly involved in regulating membrane fusion. INTRODUCTIONMembrane fusion is an essential step in all forms of vesicle trafficking and organelle assembly. Fusion is driven by a series of regulated protein-protein interactions. Many participating proteins have been identified, and their specific roles are gradually coming to light (reviewed in Jahn et al., 2003). Among these proteins are a number of ATPases.N-ethyl maleimide sensitive factor (NSF) was one of the first proteins specifically linked to membrane fusion (Wilson et al., 1989). It belongs to a family of chaperone-like ATPases known as AAA (ATPases associated with a variety of cellular activities) proteins (Neuwald et al., 1999). NSF together with ␣-SNAP (soluble NSF attachment protein) dissociates the SNARE (SNAP receptor) complexes that promote association and fusion of cellular membranes. More recently, NSF has also been implicated in other cellular processes on the basis of its ability to bind the AMPA receptor GluR2, ␤-arrestin 1, and GATE-16 (reviewed in Whiteheart et al., 2001). However, its role in SNARE disassembly and membrane fusion remains its best understood function.Not all ATP-requiring steps that lead to membrane fusion can be attributed to NSF (Goda and Pfeffer, 1991;Latterich and Schekman, 1994;Rodriguez et al., 1994;Wilson, 1995).Other ATPases must therefore be involved. One AAA protein thought to be an alternate to NSF is known as p97 (also referred to as valosin-containing protein, VCP). p97 is an abundant and highly conserved protein (Peters et al., 1990) whose cellular function has been the subject of much debate. A break in the mystery of p97's function came when it turn...

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Section: Inverse Arrangement Of Aaa Domains In Nsf and P97supporting

confidence: 86%

Distinct Roles for the AAA ATPases NSF and p97 in the Secretory Pathway

Dalal

Rosser

Cyr

et al. 2004

MBoC

165

174

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“…The Binding Domains Alone Do Not Mediate Regulation of ATPase Activity-We previously reported that p47 down-regulates the ATP hydrolysis activity of p97 (27). Since results presented here revealed that Ufd1-Npl4 uses the same mechanism of interaction with p97 as p47, we asked whether Ufd1-Npl4 regulates p97 the same way.…”

Section: Npl4 Contains a Ubiquitin Fold Domain That Mediatesmentioning

confidence: 84%

“…One aspect is that they link the ATPase to different types of ubiquitin conjugates, Ufd1-Npl4 to lysine 48 linked chains and p47 to monoubiquitylated substrates (6,21). Another aspect is the p47-mediated regulation of the ATPase activity of p97 (27). In an effort to cast light on the role of Ufd1-Npl4 and its relationship to p97, we have analyzed its structural organization and its interaction with the ATPase.…”

mentioning

confidence: 99%

The AAA ATPase p97/VCP Interacts with Its Alternative Co-factors, Ufd1-Npl4 and p47, through a Common Bipartite Binding Mechanism

Bruderer¹,

Brasseur²,

Meyer³

2004

Journal of Biological Chemistry

136

169

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The AAA ATPase p97/VCP forms complexes with different adapters to fulfill distinct cellular functions. We analyzed the structural organization of the Ufd1-Npl4 adapter complex and its interaction with p97 and compared it with another adapter, p47. We found that the binary Ufd1-Npl4 complex forms a heterodimer that cooperatively interacts with p97 via a bipartite binding mechanism. Binding site 1 (BS1) is a short hydrophobic stretch in the C-terminal domain of Ufd1. The second binding site is located at the N terminus of Npl4 and is activated upon binding of Ufd1 to Npl4. It consists of about 80 amino acids that are predicted to form a ubiquitin fold domain (UBD). Despite the lack of overall homology between Ufd1-Npl4 and p47, both adapters use identical binding mechanisms. Like the ubiquitin fold ubiquitin regulatory X (UBX) domain in p47, the Npl4-UBD interacts with p97 via the loop between its strands 3 and 4 and a conserved arginine in strand 1. Furthermore, we identified a region in p47 homologous to Ufd1-BS1. The UBD/UBX and the BS1 of both adapters interact with p97 independently, whereas homologous binding sites in both adapters compete for binding to p97. In contrast to p47, however, Ufd1-Npl4 does not regulate the ATPase activity of p97; nor does a variant of p47 that contains both binding sites but lacks the Nterminal domains. Therefore, the binding sites alone do not regulate p97 directly but rather serve as anchor points to position adapter-specific domains at critical locations to modulate p97-mediated reactions.

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“…Ufe1p and syntaxin 5) in post-fusion membranes to make them available for subsequent rounds of fusion. This model is largely based upon the Sec18p/NSF-dependent mechanism of membrane fusion and does not reconcile the many biochemical differences between these two AAA ATPases including their interaction with adapter proteins (Wilson et al, 1992;Kondo et al, 1997) and the control of ATP hydrolysis (Morgan et al, 1994;Meyer et al, 1998).…”

Section: Discussionmentioning

confidence: 99%

“…In support, adapter proteins associate with cytosolic Cdc48p/p97 hexamers (Kondo et al, 1997), whereas Sec18p/NSF binds to ␣-SNAP only in the presence of SNARE complexes (Wilson et al, 1992). In addition, the rate of ATPase hydrolysis by Cdc48p/p97 is reduced in the presence of p47 (Meyer et al, 1998), whereas NSF ATPase activity is simulated by ␣-SNAP (Morgan et al, 1994).…”

mentioning

confidence: 99%

Characterization of AtCDC48. Evidence for Multiple Membrane Fusion Mechanisms at the Plane of Cell Division in Plants

Dickey²,

et al. 2002

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The components of the cellular machinery that accomplish the various complex and dynamic membrane fusion events that occur at the division plane during plant cytokinesis, including assembly of the cell plate, are not fully understood. The most well-characterized component, KNOLLE, a cell plate-specific soluble N-ethylmaleimide-sensitive fusion protein (NSF)-attachment protein receptor (SNARE), is a membrane fusion machine component required for plant cytokinesis. Here, we show the plant ortholog of Cdc48p/p97, AtCDC48, colocalizes at the division plane in dividing Arabidopsis cells with KNOLLE and another SNARE, the plant ortholog of syntaxin 5, SYP31. In contrast to KNOLLE, SYP31 resides in defined punctate membrane structures during interphase and is targeted during cytokinesis to the division plane. In vitro-binding studies demonstrate that AtCDC48 specifically interacts in an ATP-dependent manner with SYP31 but not with KNOLLE. In contrast, we show that KNOLLE assembles in vitro into a large approximately 20S complex in an Sec18p/NSF-dependent manner. These results suggest that there are at least two distinct membrane fusion pathways involving Cdc48p/p97 and Sec18p/NSF that operate at the division plane to mediate plant cytokinesis. Models for the role of AtCDC48 and SYP31 at the division plane will be discussed.Plant cell division is completed by the highly dynamic process of de novo cell plate construction leading to the separation of two daughter cells. Formation of this unique cytokinetic organelle involves at least three key membrane fusion steps: (a) fusion of secretory vesicles across the division plane to form a membranous tubular-vesicular network, (b) consolidation of the tubular-vesicular network, and (c) fusion of the cell plate leading-edge with the original parental plasma membrane to complete division (Samuels et al., 1995). These distinct stages of cell plate biogenesis likely involve both heterotypic and homotypic membrane fusion events. In addition to the cell plate, the division plane contains an extensive endoplasmic reticulum (ER) network that has been suggested to function in the formation of the cell plate (Hepler, 1982). Assembly of cell plateassociated ER is likely to involve homotypic fusion of ER membrane within the division plane.Two homologous classes of ATPases associated with various cellular activities (AAA) proteins (Frö hlich, 2001), Sec18p N-ethylmaleimide-sensitive fusion protein (NSF) and Cdc48p/p97 (p97 is also known as VCP), regulate a variety of secretory membrane fusion processes (Acharya et al., 1995;Latterich et al., 1995;Rabouille et al., 1995). Monomers of Sec18p/NSF and Cdc48p/p97 consist of two Mg 2ϩ -dependent ATPase domains and an N-terminal substrate/adapter domain that assemble into biologically active ring-shaped oligohexamers (Peters et al., 1990; Hanson et al., 1997). Of these two AAA complexes, the biochemical function of Sec18p/NSF, which along with its cofactor, soluble NSF-attachment protein (␣-SNAP) regulates hetero-and homotypic membrane fusion, has...

show abstract

The p47 co‐factor regulates the ATPase activity of the membrane fusion protein, p97

Cited by 98 publications

References 25 publications

Distinct Roles for the AAA ATPases NSF and p97 in the Secretory Pathway

Distinct Roles for the AAA ATPases NSF and p97 in the Secretory Pathway

The AAA ATPase p97/VCP Interacts with Its Alternative Co-factors, Ufd1-Npl4 and p47, through a Common Bipartite Binding Mechanism

Characterization of AtCDC48. Evidence for Multiple Membrane Fusion Mechanisms at the Plane of Cell Division in Plants

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