CYTOSKELETAL POLYPEPTIDES - CELL-TYPE-SPECIFIC MARKERS USEFUL IN INVESTIGATIVE OTORHINOLARYNGOLOGY

In the last decade, it has been established that eukaryotic cells poss ess a cytoskeleton, i.e. an integrated cytoplasmic network of microfil aments (MFs), microtubules (MTs) and intermediate filaments (IFs). Mor eover, certain cell membrane specializations as well as the inner lami na of the nuclear membrane also participate in the cytoskeletal struct ure. Although this definition of the cytoskeleton is up to date it is obvious that the future course of cell biology will be reflected in a revised definition. While the bulk of structural polypeptides involved were characterized at regular intervals, surprisingly, the function o f the cytoskeleton remained largely speculative and is still less prec isely defined. The most widely postulated function concerns mechanical support and integration of diverse cellular activities and thus refer s to cellular architecture. Briefly, the mechanical function is though t to involve cell movement, adhesive interaction with the extracellula r matrix and neighbouring cells, as well as the stabilization of cell shape. The integrative function refers to intracellular movement, i.e. transport and positioning to the appropriate locations of organelles, intracellular particles, RNA and proteins. It has been established fr om numerous investigations that (certain) cytoskeletal polypeptides pr ovide significant information about the cellular origin and differenti ation state. This consideration constitutes the most prominent reflect ion underlying this review. Furthermore, this appreciation encourages additional efforts to explore these markers in normal and pathological conditions. The first purpose of this review is briefly to summarize our present comprehension of the molecular components of the cytoskele ton, restricted to the filamentous trinity for practical reasons. The second and main aim is to survey the field with respect to otorhinolar yngology-related issues. To the author's knowledge, this has not been dealt with in the past. In bridging this gap in the literature, I hope to provoke additional interest in one of the fastest moving areas of cell biology. A comprehensive review covering the whole cytoskeleton h as been covered by Preston et al. (The Cytoskeleton and Cell Motility. Blackie, Glasgow and London, 1990, pp. 7-69, 188-191). Additional inf ormation on the participating substructures is provided in the text, i nclusive of last year's reviews.