The non-muscle functions of actinins: an update

Abstract

α-Actinins are a major class of actin filament cross-linking proteins expressed in virtually all cells. In muscle, actinins cross-link thin filaments from adjacent sarcomeres. In non-muscle cells, different actinin isoforms play analogous roles in cross-linking actin filaments and anchoring them to structures such as cell-cell and cell-matrix junctions. Although actinins have long been known to play roles in cytokinesis, cell adhesion and cell migration, recent studies have provided further mechanistic insights into these functions. Roles for actinins in synaptic plasticity and membrane trafficking events have emerged more recently, as has a 'non-canonical' function for actinins in transcriptional regulation in the nucleus. In the present paper we review recent advances in our understanding of these diverse cell biological functions of actinins in non-muscle cells, as well as their roles in cancer and in genetic disorders affecting platelet and kidney physiology. We also make two proposals with regard to the actinin nomenclature. First, we argue that naming actinin isoforms according to their expression patterns is problematic and we suggest a more precise nomenclature system. Secondly, we suggest that the α in α-actinin is superfluous and can be omitted.

Roles and Potential Clinical Applications of Intermediate Filament Proteins in Brain Tumors

“…66 Synemin downregulation with specific shRNA reduces the quantity of polymerized actin and the amount of α-actinin associated with polymerized actin. As α-actinin binds to synemin and also affects the organization and stability of polymerized actin, 67 synemin may contribute to astrocytoma motility by regulating interaction of α-actinin with F-actin. 66 Furthermore, synemin downregulation also reduced astrocytoma cell proliferation 66,68 by upregulating cyclin-dependent kinase inhibitors, p21 Cip1/Waf1 and p27 Kip1 , and causing hypophosphorylation of retinoblastoma protein.…”

Literature Review of Turkish Sportsmen in Terms of ACTN3 R577X Polymorphism

“…ACTN1 ve ACTN4 alternatif splays mekanizması ile sentez edilir. Merkezi sinir sisteminde ve düz kaslarda Ca ++ duyarsız varyantları ile birçok dokuda eksprese edilen Ca ++ duyarlı formları bulunmaktadır (2). ACTN1, birçok hücrede aktin filamentlerinin birbirine bağlanmasını sağlayarak bu yapıların hücre-hücre ve hücre-matriks bağlantı yapılarına daha sıkı bağlan-malarını sağlamaktadır, bu nedenle sitokinez, hücre adezyonu ve hücre hareketleri gibi hücresel işlevlerde rol oynamaktadır (3).…”

Neuronal migration is mediated by inositol hexakisphosphate kinase 1 via α-actinin and focal adhesion kinase

“…α-Actinin is a major determinant of stress fibers, stabilizing them and enhancing their ability to generate tension (10,11). α-Actinin also binds integrins, influences cellular adhesions, and is required for migration and spreading of many cell types (12,13).…”