scholarly journals Mini-review: Synaptojanin 1 and its Implications in Membrane Trafficking

2021 ◽  
pp. 136288
Author(s):  
Hassaam Choudhry ◽  
Meha Aggarwal ◽  
Ping-Yue Pan
Keyword(s):  
Membrane Trafficking ◽  
Synaptojanin 1

scholarly journals InsP3-mediated intracellular calcium signalling is altered by expression of synaptojanin-1

2004 ◽  
Vol 382 (2) ◽  
pp. 687-694 ◽  
Author(s):  
Friedrich W. JOHENNING ◽  
Markus R. WENK ◽  
Per UHLÉN ◽  
Brenda DeGRAY ◽  
Eunkyung LEE ◽  
...  
Keyword(s):  
Intracellular Calcium ◽  
Membrane Trafficking ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Calcium Signalling ◽  
Physiological Role ◽  
Actin Dynamics ◽  
Phosphatase Domain ◽  
Phosphoinositide Phosphatase ◽  
Synaptojanin 1

Phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] plays an important physiological role as a precursor for the InsP3-mediated intracellular calcium (Ca2+) signalling cascade. It also regulates membrane trafficking, actin function and transmembrane proteins. SJ-1 (synaptojanin-1), a phosphoinositide phosphatase, regulates the turnover of a PtdIns(4,5)P2 pool involved in clathrin and actin dynamics at the cell surface. We tested the interrelationship of this pool with PtdIns(4,5)P2 pools involved in Ca2+ signalling by expressing in Chinese-hamster ovary cells full-length SJ-1 or its 5-Pase (inositol 5-phosphatase) domain. SJ-1 significantly attenuated the generation of Ca2+ oscillations induced by ATP and the 5-Pase domain mimicked this effect. These changes correlated with increased PtdIns(4,5)P2 phosphatase activity of cellular extracts. Overexpression of the endoplasmic reticulum-anchored PtdIns(4)P phosphatase Sac1 did not affect Ca2+ oscillations, although it increased the Ca2+ efflux rate from intracellular stores. The ability of SJ-1 to alter intracellular Ca2+ signalling indicates a close functional interrelationship between plasma membrane PtdIns(4,5)P2 pools that control actin and endocytosis and those involved in the regulation of specific spatio-temporal Ca2+ signals.

The Phosphoinositide Signal Transduction Pathway in the Pathogenesis of Alzheimer’s Disease

2018 ◽  
Vol 15 (4) ◽  
pp. 355-362 ◽  
Author(s):  
Vincenza Rita Lo Vasco
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Signal Transduction ◽  
Membrane Trafficking ◽  
Hormone Secretion ◽  
Signal Transduction Pathway ◽  
Brain Morphology ◽  
Signal Transduction Pathways ◽  
Transduction Pathway ◽  
Cell Functions

Background: During aging and in age-associated disorders, such as Alzheimer's Disease (AD), learning abilities decline. Probably, disturbances in signal transduction in brain cells underlie the cognitive decline. The phosphorylation/dephosphorylation imbalance occurring in degenerating neurons was recently related to abnormal activity of one or more signal transduction pathways. AD is known to be associated with altered neuronal Ca<sup>2+</sup> homeostasis, as Ca<sup>2+</sup> accumulates in affected neurons leading to functional impairment. It is becoming more and more evident the involvement of signal transduction pathways acting upon Ca<sup>2+</sup> metabolism and phosphorylation regulation of proteins. A growing interest raised around the role of signal transduction systems in a number of human diseases including neurodegenerative diseases, with special regard to the systems related to the phosphoinositide (PI) pathway and AD. The PI signal transduction pathway plays a crucial role, being involved in a variety of cell functions, such as hormone secretion, neurotransmitter signal transduction, cell growth, membrane trafficking, ion channel activity, cytoskeleton regulation, cell cycle control, apoptosis, cell and tissue polarity, and contributes to regulate the Ca<sup>2+</sup> levels in the nervous tissue. Conclusion: A number of observations indicated that PI-specific phospholipase C (PLC) enzymes might be involved in the alteration of neurotransmission. To understand the role and the timing of action of the signalling pathways recruited during the brain morphology changes during the AD progression might help to elucidate the aetiopathogenesis of the disease, paving the way to prognosis refinement and/or novel molecular therapeutic strategies.

scholarly journals An FYVE-Domain-Containing Protein, PsFP1, Is Involved in Vegetative Growth, Oxidative Stress Response and Virulence of Phytophthora sojae

2021 ◽  
Vol 22 (12) ◽  
pp. 6601
Author(s):  
Jinhui Zhang ◽  
Xiaoran Du ◽  
Xin Zhou ◽  
Duo Jin ◽  
Jianqiang Miao ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Membrane Trafficking ◽  
Vegetative Growth ◽  
Genome Mining ◽  
Gene Replacement ◽  
Wide Distribution ◽  
Stress Sensitivity ◽  
Phytophthora Sojae ◽  
Knock Out ◽  
Fyve Domain

Proteins that contain the FYVE zinc-finger domain are recruited to PtdIns3P-containing membranes, participating in numerous biological processes such as membrane trafficking, cytoskeletal regulation, and receptor signaling. However, the genome-wide distribution, evolution, and biological functions of FYVE-containing proteins are rarely reported for oomycetes. By genome mining of Phytophthora sojae, two proteins (PsFP1 and PsFP2) with a combination of the FYVE domain and the PX domain (a major phosphoinositide binding module) were found. To clarify the functions of PsFP1 and PsFP2, the CRISPR/Cas9-mediated gene replacement system was used to knock out the two genes respectively. Only heterozygous deletion mutants of PsFP1 were recovered, and the expression level of PsFP1 in the heterozygous knockout transformants was significantly down-regulated. These PsFP1 mutants showed a decrease in mycelial growth and pathogenicity and were more sensitive to hydrogen peroxide. These phenotypes were recovered to the level of wild-type by overexpression PsFP1 gene in the PsFP1 heterozygous knockout transformant. In contrast, deletion of PsFP2 had no significant effect on vegetative growth, asexual and sexual reproduction, pathogenicity, or oxidative stress sensitivity. PsFP1 was primarily localized in vesicle-like structures and both the FYVE and PX domains are important for its localization. Overall, our results indicate that PsFP1 plays an important role in the vegetative growth and virulence of P. sojae.

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