Here, we report the novel use of the ethonolic leaf extract of Piper betle for gold nanoparticle (AuNP) synthesis. The successful formation of AuNPs was confirmed by UV-visible spectroscopy, and different parameters such as leaf extract concentration (2%), gold salt concentration (0.5 mM), and time (18 s) were optimized. The synthesized AuNPs were characterized with different biophysical techniques such as transmission electron microscopy (TEM), Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), and energy-dispersive X-ray spectroscopy (EDX). TEM experiments showed that nanoparticles were of various shapes and sizes ranging from 10 to 35 nm. FT-IR spectroscopy revealed that AuNPs were functionalized with biomolecules that have primary amine group –NH2, carbonyl group, –OH groups, and other stabilizing functional groups. EDX showed the presence of the elements on the surface of the AuNPs. FT-IR and EDX together confirmed the presence of biomolecules bounded on the AuNPs. Cytotoxicity of the AuNPs was tested on HeLa and MCF-7 cancer cell lines, and they were found to be nontoxic, indicating their biocompatibility. Thus, synthesized AuNPs have potential for use in various biomedical applications.

Phospholipases are ubiquitous enzymes that hydrolyze phospholipids. Based on the cleavage site of the ester linkage in the substrate phospholipids, phospholipases are classified into four major types, phospholipase A (PLA), phospholipase B (PLB), phospholipase C (PLC), and phospholipase D (PLD), which are further classified into various subtypes. Phospholipases hydrolyze phospholipids into various signaling products including phosphatidic acid (PA), diacylglycerol (DAG), free fatty acids (FFAs), and lyso-phospholipids (LPLs). These signaling products regulate numerous processes such as cytoskeletal dynamics, growth, homeostasis, membrane remodeling, nutrient acquisition, secretion, signal transduction, stress tolerance, sexual development, and virulence in various organisms including fungi. Due to these key cellular roles, phospholipases are also promising targets in diagnostic and therapeutic applications. In this review, we discuss current knowledge about the cellular roles of different classes of phospholipases in fungi.

The neuronal calcium sensor-1 (NCS-1) possesses a consensus signal for N-terminal myristoylation and four EF-hand Ca(2+)-binding sites, and mediates the effects of cytosolic Ca(2+). Minute changes in free intracellular Ca(2+) are quickly transformed into changes in the activity of several kinases including calcium/calmodulin-dependent protein kinases (Ca(2+)/CaMKs) that are involved in regulating many eukaryotic cell functions. However, our current knowledge of NCS-1 and Ca(2+)/CaMKs comes mostly from studies of the mammalian enzymes. Thus far very few fungal homologues of NCS-1 and Ca(2+)/CaMKs have been characterized and little is known about their cellular roles. In this minireview, we describe the known sequences, interactions with target proteins and cellular roles of NCS-1 and Ca(2+)/CaMKs in fungi.

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Calcium (Ca 2+ ) is a universal signalling molecule of life. The Ca 2+ signalling is an evolutionarily conserved process from prokaryotes to eukaryotes. Ca 2+ at high concentration is deleterious to the cell; therefore, cell maintains a low resting level of intracellular free Ca 2+ concentration ([Ca 2+ ] c ). The resting [Ca 2+ ] c is tightly regulated, and a transient increase of the [Ca 2+ ] c initiates a signalling cascade in the cell. Ca 2+ signalling plays an essential role in various processes, including growth, development, reproduction, tolerance to stress conditions, and virulence in fungi. In this review, we describe the evolutionary aspects of Ca 2+ signalling and cell functions of major Ca 2+ signalling proteins in different fungi.