The Sprouty-related protein, Spred-1, localizes in a lipid raft/caveola and inhibits ERK activation in collaboration with caveolin-1

Division of Molecular and Cellular Immunology, Medical Institute of Bioregulation, Kyushu University, Higashi-ku, Fukuoka 812-8582, Japan.
Genes to Cells (Impact Factor: 2.81). 10/2005; 10(9):887-95. DOI: 10.1111/j.1365-2443.2005.00886.x
Source: PubMed


Caveolin-1 (Cav-1) has been suggested to function as a negative regulator of mitogen-stimulated proliferation and the Ras-p42/44 ERK (MAP kinase) pathway in a variety of cell types. However, the molecular basis of this suppression has not been clarified. Spred/Sprouty family proteins are also negative regulators of the ERK pathway by interacting with Raf-1. The Spred/Sprouty family proteins contain a cysteine-rich (CR) domain at the C-terminus, which is thought to be palmitoylated like Cav-1 and necessary for membrane anchoring. In this study, we demonstrated that Spred-1 localized in cholesterol-rich membrane raft/caveola fractions and interacted with Cav-1. To clarify the biological effect of Cav-1/Spred-1 interaction, we used hematopoietic cells that lacked expression of caveolins but expressed Spred-1. Forced expression of Cav-1 suppressed SCF- and IL-3-induced proliferation and ERK activation. Furthermore, forced expression of exogenous Spred-1 in Cav-1-expressing cells further suppressed proliferation and ERK activation. These data suggest that Spred-1 inhibits ERK activation in collaboration with Cav-1.

Download full-text


Available from: Takahito Sanada, Oct 29, 2014
11 Reads
  • Source
    • "Likewise, it remains to be determined if Spry1 plays an inhibitory role in all T cell subsets. While the precise role of Spry1 in these systems has yet to be identified, another member of the sprouty family Sprouty-related Ena/VASP homology 1-domain-containing protein 1 (Spred1) has been shown to inhibit IL-3-induced MAP-kinase activation in hematopoietic cells [17]. Additionally, Spred1 has been shown to negatively regulate IL-5-induced eosnophilia in a mouse model of asthma [18]. "
    [Show abstract] [Hide abstract]
    ABSTRACT: TCR-induced NF-AT activation leads to the expression of both activating and inhibitory proteins. Previously, we had identified Egr-2 and Egr-3 as NF-AT-induced transcription factors which promote the inhibition of T cell activation. In this report we identify Sprouty1 as a downstream target of Egr-3. CD4(+) T cells lacking Spry1 demonstrate enhanced proliferation and cytokine production. Likewise, Spry1(Flox/Flox) Lck Cre CD8(+) T cells display increased cytolytic activity. Mechanistically, Spry1 acts at the level of PLC-γ promoting the inhibition of both Ca(++) induced NF-AT activation and MAP-kinase induced AP-1 activation while sparing NF-κB signaling. In vivo, mice in which Spry1 is selectively deleted in T cells demonstrate enhanced responses to a tumor vaccine and subsequently reject tumors more robustly than Wt mice. These findings suggest that targeting Spry1 might prove to be a novel means of enhancing tumor immunotherapy.
    PLoS ONE 11/2012; 7(11):e49801. DOI:10.1371/journal.pone.0049801 · 3.23 Impact Factor
  • Source
    • "The KBD is involved but not essential in ERK suppression [Nonami et al., 2004; Wakioka et al., 2001]. Spred1 localizes in the lipid raft/caveolar fraction by virtue of its C-terminal part (SPR) and interacts with caveolin [Nonami et al., 2005]. Spred1 expression has an effect on the actin cytoskeleton via its N-terminal EVH-1 and C-terminal SPR domain. "
    [Show abstract] [Hide abstract]
    ABSTRACT: Legius syndrome presents as a mild neurofibromatosis type 1 (NF1) phenotype. Multiple café-au-lait spots and macrocephaly are present with or without axillary or inguinal freckling. Other typical NF1-associated features (Lisch nodules, bone abnormalities, neurofibromas, optic pathway gliomas, and malignant peripheral nerve sheath tumors) are systematically absent. Legius syndrome is caused by germline loss-of-function SPRED1 mutations, resulting in overactivation of the RAS-MAPK signal transduction cascade. The first families were identified in 2007. Here, we review all identified SPRED1 mutations and summarize molecular, clinical, and functional data. All mutations have been deposited in a database created using the Leiden Open Variation Database software and accessible at At present, the database contains 89 different mutations identified in 146 unrelated probands, including 16 new variants described for the first time. The database contains a spectrum of mutations: 29 missense, 28 frameshift, 19 nonsense, eight copy number changes, two splicing, one silent, one in-frame deletion and a mutation affecting the initiation codon. Sixty-three mutations and deletions are definitely pathogenic or most likely pathogenic, eight SPRED1 mutations are probably benign rare variants, and 17 SPRED1 missense mutations are still unclassified and need further family and functional studies to help with the interpretation. Hum Mutat 33:1538-1546, 2012. © 2012 Wiley Periodicals, Inc.
    Human Mutation 11/2012; 33(11):1538-46. DOI:10.1002/humu.22152 · 5.14 Impact Factor
  • Source
    • "The majority of reported Spred1 mutations produce a premature stop codon, resulting in C-terminally truncated protein products (Brems et al. 2007; Messiaen et al. 2009; Pasmant et al. 2009; Spurlock et al. 2009; Muram-Zborovski et al. 2010; Denayer et al. 2011; Laycock-van Spyk et al. 2011; Spencer et al. 2011). As the SPR domain has previously been reported to target Spred1 to the plasma membrane via interactions with phospholipids and caveolin-1 (Lim et al. 2002; Nonami et al. 2005), we surmised that the truncated mutants were unable to function as a result of mislocalization . To test this hypothesis, we artificially localized the Spred1 C-terminal truncation mutant (M266fsX4) to the membrane by fusing it to the membrane targeting CAAX motif of Kras4B (Fig. 2A). "
    [Show abstract] [Hide abstract]
    ABSTRACT: The Ras/mitogen-activated protein kinase (MAPK) pathway plays a critical role in transducing mitogenic signals from receptor tyrosine kinases. Loss-of-function mutations in one feedback regulator of Ras/MAPK signaling, SPRED1 (Sprouty-related protein with an EVH1 domain), cause Legius syndrome, an autosomal dominant human disorder that resembles Neurofibromatosis-1 (NF1). Spred1 functions as a negative regulator of the Ras/MAPK pathway; however, the underlying molecular mechanism is poorly understood. Here we show that neurofibromin, the NF1 gene product, is a Spred1-interacting protein that is necessary for Spred1's inhibitory function. We show that Spred1 binding induces the plasma membrane localization of NF1, which subsequently down-regulates Ras-GTP levels. This novel mechanism for the regulation of neurofibromin provides a molecular bridge for understanding the overlapping pathophysiology of NF1 and Legius syndrome.
    Genes & development 07/2012; 26(13):1421-6. DOI:10.1101/gad.190876.112 · 10.80 Impact Factor
Show more