A matricellular protein and EGF-like repeat signalling in the social amoebozoan Dictyostelium discoideum

Abstract

Matricellular proteins interact with the extracellular matrix (ECM) and modulate cellular processes by binding to cell surface receptors and initiating intracellular signal transduction. Their association with the ECM and the ability of some members of this protein family to regulate cell motility have opened up new avenues of research to investigate their functions in normal and diseased cells. In this review, we summarize the research on CyrA, an ECM calmodulin-binding protein in Dictyostelium. CyrA is proteolytically cleaved into smaller EGF-like (EGFL) repeat containing cleavage products during development. The first EGFL repeat of CyrA binds to the cell surface and activates a novel signalling pathway that modulates cell motility in this model organism. The similarity of CyrA to the most well-characterized matricellular proteins in mammals allows it to be designated as the first matricellular protein identified in Dictyostelium.

Calmodulin‐mediated events during the life cycle of the amoebozoan Dictyostelium discoideum

“…DdEGFL1 functions independently of the pathway regulating the response of cells to cAMP, since the peptide increases the movement of cells lacking the cAMP receptors CarA and CarC, as well as cells that lack the G‐proteins coupled to these receptors (Huber & O'Day, ). Instead, the peptide activates a novel pathway involving Ca 2+ , CaM, RasG, PI3K, and PLA2, which leads to increased amounts of actin and myosin II heavy chain in the cytoskeleton (Huber & O'Day, , , ). DdEGFL1 also sustains the threonine phosphorylation of the cytoskeletal protein vinculin B (VinB) during the early stages of D. discoideum development (Huber & O'Day, , ).…”

Matricellular Proteins and Related ADAMTS Genes in Infertility

“…Matricellular proteins constitute an interface favoring the interaction of other matricellular proteins and ECM proteins (Figure 2). 27 Outcomes of numerous studies in functions of matricellular proteins, ADAMTSs and ECM mesh in infertility are classified according to fertilization stages as follows.…”

A novel phagocytic receptor (CgNimC) from Pacific oyster Crassostrea gigas with lipopolysaccharide and gram-negative bacteria binding activity

“…Nimrod was reported to involve in the immune response against the invasion of pathogens [14,16], and the spatial-temporal expression responding to the challenge of pathogens would be helpful to understand its specific roles in immune system. In the present study, the mRNA expression level of CgNimC was remarkably higher in hemocytes and mantle than that in other tissues.…”

“…The consensus sequence of NIM repeat (CXPXCXXXCXNGXCXXPXXCXCXXGY) is shifted by one cysteine unit relative to the typical EGF repeat consensus (xxxxCx 2e7 Cx 1e4 (G/A)xCx 1e13 ttaxCx-CxxGax 1e6 GxxCx) [9]. The EGF-like repeat, as single entity or be arranged as multiple tandem repeat [13], is a widespread, highly variable domain participating in a wide variety of cellular activities including cell motility and chemotaxis [14,15]. Nimrod proteins can be classified into three categories based on the characteristic structure of NIM domain [9,16,17].…”