Src Homology 3-Domain Growth Factor Receptor-Bound 2-Like (Endophilin) Interacting Protein 1, a Novel Neuronal Protein that Regulates Energy Balance

Abstract To identify genes involved in the central regulation of energy balance, we compared hypothalamic mRNA from lean and obese Psammomys obesus, a polygenic model of obesity, using differential display PCR. One mRNA transcript was observed to be elevated in obese, and obese diabetic, P. obesus compared with lean animals and was subsequently found to be increased 4-fold in the hypothalamus of lethal yellow agouti (Ay/a) mice, a murine model of obesity and diabetes. Intracerebroventricular infusion of antisense oligonucleotide targeted to this transcript selectively suppressed its hypothalamic mRNA levels and resulted in loss of body weight in both P. obesus and Sprague Dawley rats. Reductions in body weight were mediated by profoundly reduced food intake without a concomitant reduction in metabolic rate. Yeast two-hybrid screening, and confirmation in mammalian cells by bioluminescence resonance energy transfer analysis, demonstrated that the protein it encodes interacts with endophilins, mediators of synaptic vesicle recycling and receptor endocytosis in the brain. We therefore named this transcript Src homology 3-domain growth factor receptor-bound 2-like (endophilin) interacting protein 1 (SGIP1). SGIP1 encodes a large proline-rich protein that is expressed predominantly in the brain and is highly conserved between species. Together these data suggest that SGIP1 is an important and novel member of the group of neuronal molecules required for the regulation of energy homeostasis.

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SGIP1α, but Not SGIP1, is an Ortholog of FCHo Proteins and Functions as an Endocytic Regulator

Frontiers in Cell and Developmental Biology ◽

10.3389/fcell.2021.801420 ◽

2021 ◽

Vol 9 ◽

Author(s):

Sang-Eun Lee ◽

Eunji Cho ◽

Soomin Jeong ◽

Yejij Song ◽

Seokjo Kang ◽

...

Keyword(s):

Energy Homeostasis ◽

Growth Factor Receptor ◽

Domain Growth ◽

Interacting Protein ◽

Src Homology 3 ◽

Functional Consequences ◽

Src Homology 3 Domain ◽

Src Homology ◽

Growth Factor Receptor Bound

Src homology 3-domain growth factor receptor-bound 2-like interacting protein 1 (SGIP1), originally known as a regulator of energy homeostasis, was later found to be an ortholog of Fer/Cip4 homology domain-only (FCHo) proteins and to function during endocytosis. SGIP1α is a longer splicing variant in mouse brains that contains additional regions in the membrane phospholipid-binding domain (MP) and C-terminal region, but functional consequences with or without additional regions between SGIP1 and SGIP1α remain elusive. Moreover, many previous studies have either inadvertently used SGIP1 instead of SGIP1α or used the different isoforms with or without additional regions indiscriminately, resulting in further confusion. Here, we report that the additional region in the MP is essential for SGIP1α to deform membrane into tubules and for homo-oligomerization, and SGIP1, which lacks this region, fails to perform these functions. Moreover, only SGIP1α rescued endocytic defects caused by FCHo knock-down. Thus, our results indicate that SGIP1α, but not SGIP1, is the functional ortholog of FCHos, and SGIP1 and SGIP1α are not functionally redundant. These findings suggest that caution should be taken in interpreting the role of SGIP1 in endocytosis.

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Affinity chromatography for purification of the modular protein growth factor receptor-bound protein 2 and development of a screening test for growth factor receptor-bound protein 2 Src homology 3 domain inhibitor using peroxidase-linked ligand

Analytical Biochemistry ◽

10.1016/j.ab.2005.12.032 ◽

2006 ◽

Vol 351 (1) ◽

pp. 93-99 ◽

Cited By ~ 2

Author(s):

B. Gril ◽

W.Q. Liu ◽

C. Lenoir ◽

C. Garbay ◽

M. Vidal

Keyword(s):

Growth Factor ◽

Affinity Chromatography ◽

Screening Test ◽

Growth Factor Receptor ◽

Src Homology 3 ◽

Src Homology 3 Domain ◽

Src Homology ◽

Growth Factor Receptor Bound

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The activation mechanism of ACK1 (activated Cdc42-associated tyrosine kinase 1)

Biochemical Journal ◽

10.1042/bj20111575 ◽

2012 ◽

Vol 445 (2) ◽

pp. 255-264 ◽

Cited By ~ 19

Author(s):

Qiong Lin ◽

Jian Wang ◽

Chandra Childress ◽

Wannian Yang

Keyword(s):

Cell Adhesion ◽

Growth Factor ◽

Tyrosine Kinase ◽

Molecular Mechanism ◽

Growth Factor Receptor ◽

Activation Mechanism ◽

Src Homology 3 ◽

Src Homology 3 Domain ◽

Src Homology ◽

Epidermal Growth

ACK [activated Cdc42 (cell division cycle 42)-associated tyrosine kinase; also called TNK2 (tyrosine kinase, non-receptor, 2)] is activated in response to multiple cellular signals, including cell adhesion, growth factor receptors and heterotrimeric G-protein-coupled receptor signalling. However, the molecular mechanism underlying activation of ACK remains largely unclear. In the present study, we demonstrated that interaction of the SH3 (Src homology 3) domain with the EBD [EGFR (epidermal growth factor receptor)-binding domain] in ACK1 forms an auto-inhibition of the kinase activity. Release of this auto-inhibition is a key step for activation of ACK1. Mutation of the SH3 domain caused activation of ACK1, independent of cell adhesion, suggesting that cell adhesion-mediated activation of ACK1 is through releasing the auto-inhibition. A region at the N-terminus of ACK1 (Leu10–Leu14) is essential for cell adhesion-mediated activation. In the activation of ACK1 by EGFR signalling, Grb2 (growth-factor-receptor-bound protein 2) mediates the interaction of ACK1 with EGFR through binding to the EBD and activates ACK1 by releasing the auto-inhibition. Furthermore, we found that mutation of Ser445 to proline caused constitutive activation of ACK1. Taken together, our studies have revealed a novel molecular mechanism underlying activation of ACK1.

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The Small 11-kDa Protein from B19 Parvovirus Binds Growth Factor Receptor-Binding Protein 2 in Vitro in a Src Homology 3 Domain/Ligand-Dependent Manner

Virology ◽

10.1006/viro.2001.1217 ◽

2001 ◽

Vol 291 (2) ◽

pp. 285-291 ◽

Cited By ~ 22

Author(s):

Mannie M.Y. Fan ◽

Lillian Tamburic ◽

Cynthia Shippam-Brett ◽

Darren B. Zagrodney ◽

Caroline R. Astell

Keyword(s):

Growth Factor ◽

Receptor Binding ◽

Growth Factor Receptor ◽

Dependent Manner ◽

Src Homology 3 ◽

B19 Parvovirus ◽

Src Homology 3 Domain ◽

Src Homology ◽

Receptor Binding Protein

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NS5A, a nonstructural protein of hepatitis C virus, binds growth factor receptor-bound protein 2 adaptor protein in a Src homology 3 domain/ligand-dependent manner and perturbs mitogenic signaling

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.96.10.5533 ◽

1999 ◽

Vol 96 (10) ◽

pp. 5533-5538 ◽

Cited By ~ 166

Author(s):

S.-L. Tan ◽

H. Nakao ◽

Y. He ◽

S. Vijaysri ◽

P. Neddermann ◽

...

Keyword(s):

Hepatitis C Virus ◽

Hepatitis C ◽

Nonstructural Protein ◽

Growth Factor Receptor ◽

Adaptor Protein ◽

Dependent Manner ◽

Src Homology 3 ◽

Src Homology 3 Domain ◽

Src Homology ◽

Growth Factor Receptor Bound

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A Src Homology 3-binding Sequence on the C Terminus of Sprouty2 Is Necessary for Inhibition of the Ras/ERK Pathway Downstream of Fibroblast Growth Factor Receptor Stimulation

Journal of Biological Chemistry ◽

10.1074/jbc.m604044200 ◽

2006 ◽

Vol 281 (40) ◽

pp. 29993-30000 ◽

Cited By ~ 46

Author(s):

Dieu-Hung Lao ◽

Sumana Chandramouli ◽

Permeen Yusoff ◽

Chee Wai Fong ◽

Tzuen Yih Saw ◽

...

Keyword(s):

Growth Factor ◽

Fibroblast Growth Factor Receptor ◽

Growth Factor Receptor ◽

Erk Pathway ◽

Fibroblast Growth ◽

Receptor Stimulation ◽

Src Homology 3 ◽

C Terminus ◽

Src Homology ◽

Binding Sequence

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Nuclear Magnetic Resonance Solution Structure of the Growth Factor Receptor-Bound Protein 2 Src Homology 2 Domain

Biochemistry ◽

10.1021/bi952615s ◽

1996 ◽

Vol 35 (36) ◽

pp. 11852-11864 ◽

Cited By ~ 12

Author(s):

Kevin H. Thornton ◽

W. Tom Mueller ◽

Patrick McConnell ◽

Guochang Zhu ◽

Alan R. Saltiel ◽

...

Keyword(s):

Nuclear Magnetic Resonance ◽

Growth Factor ◽

Magnetic Resonance ◽

Solution Structure ◽

Growth Factor Receptor ◽

Src Homology 2 ◽

Resonance Solution ◽

Src Homology ◽

Src Homology 2 Domain ◽

Growth Factor Receptor Bound

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EAST, an Epidermal Growth Factor Receptor- and Eps15-associated Protein with Src Homology 3 and Tyrosine-based Activation Motif Domains

Journal of Biological Chemistry ◽

10.1074/jbc.273.33.21408 ◽

1998 ◽

Vol 273 (33) ◽

pp. 21408-21415 ◽

Cited By ~ 33

Author(s):

Olli Lohi ◽

Anssi Poussu ◽

Jari Meriläinen ◽

Sakari Kellokumpu ◽

Veli-Matti Wasenius ◽

...

Keyword(s):

Epidermal Growth Factor Receptor ◽

Growth Factor ◽

Epidermal Growth Factor ◽

Growth Factor Receptor ◽

Src Homology 3 ◽

Src Homology ◽

Epidermal Growth ◽

Activation Motif

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Selectivity and Mechanism of Action of a Growth Factor Receptor-Bound Protein 2 Src Homology 2 Domain Binding Antagonist

Journal of Medicinal Chemistry ◽

10.1021/jm800523u ◽

2008 ◽

Vol 51 (23) ◽

pp. 7459-7468 ◽

Cited By ~ 7

Author(s):

Alessio Giubellino ◽

Zhen-Dan Shi ◽

Lisa M. Miller Jenkins ◽

Karen M. Worthy ◽

Lakshman K. Bindu ◽

...

Keyword(s):

Growth Factor ◽

Mechanism Of Action ◽

Growth Factor Receptor ◽

Src Homology 2 ◽

Src Homology ◽

Src Homology 2 Domain ◽

Growth Factor Receptor Bound

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Amphiphysin Heterodimers: Potential Role in Clathrin-mediated Endocytosis

Molecular Biology of the Cell ◽

10.1091/mbc.8.10.2003 ◽

1997 ◽

Vol 8 (10) ◽

pp. 2003-2015 ◽

Cited By ~ 175

Author(s):

Patrick Wigge ◽

Katinka Köhler ◽

Yvonne Vallis ◽

Christopher A. Doyle ◽

David Owen ◽

...

Keyword(s):

Nerve Terminals ◽

Coated Pits ◽

Cos Cells ◽

Src Homology 3 ◽

Brain Extracts ◽

Src Homology 3 Domain ◽

Src Homology ◽

Transferrin Uptake ◽

The Brain

Amphiphysin (Amph) is a src homology 3 domain-containing protein that has been implicated in synaptic vesicle endocytosis as a result of its interaction with dynamin. In a screen for novel members of the amphiphysin family, we identified Amph2, an isoform 49% identical to the previously characterized Amph1 protein. The subcellular distribution of this isoform parallels Amph1, both being enriched in nerve terminals. Like Amph1, a role in endocytosis at the nerve terminal is supported by the rapid dephosphorylation of Amph2 on depolarization. Importantly, the two isoforms can be coimmunoprecipitated from the brain as an equimolar complex, suggesting that the two isoforms act in concert. As determined by cross-linking of brain extracts, the Amph1–Amph2 complex is a 220- to 250-kDa heterodimer. COS cells transfected with either Amph1 or Amph2 show greatly reduced transferrin uptake, but coexpression of the two proteins rescues this defect, supporting a role for the heterodimer in clathrin-mediated endocytosis. Although the src homology 3 domains of both isoforms interact with dynamin, the heterodimer can associate with multiple dynamin molecules in vitro and activates dynamin’s GTPase activity. We propose that it is an amphiphysin heterodimer that drives the recruitment of dynamin to clathrin-coated pits in endocytosing nerve terminals.

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