Twenty years have elapsed since cytoplasmic proteins exhibiting high-affinity binding of long-chain fatty acids were first identified (Ockner et al., Science 177:56-58, 1972). These cellular fatty acid-binding proteins (FABPs) are now well established to comprise a ligand-defined group of macromolecules belonging to a family of cytoplasmic lipid binding proteins. Unique features of the FABPs are the existence of distinct types of FABP and that these are found in a variety of tissues in remarkable abundance, with some cells expressing more than one type. The physiological significance of the FABPs has only partly been elucidated. By increasing the cytoplasmic solubilization of fatty acids, the cellular FABPs are considered to function primarily in intracellular fatty acid transport, but may also be assigned important regulatory roles in cellular lipid homeostasis as well as in the modulation of cell growth and differentiation. The broad interests in cellular FABPs has led to the organization of the 1st International Workshop on Fatty Acid-Binding Protein, held in Maastricht, the Netherlands, in 1989. Prompted by the success of the first meeting, the 2nd International Workshop on Fatty-Acid-Binding Proteins, which was held again in Maastricht, on August 31 and September 1, 1992, brought together scientific scpecialists in the field of FABP research for two days of intensive and fruitful discussion. This volume is a collection of selected papers from this conference, and thus provides the state-of-the-art knowledge of cellular FABPs. The contributors to this issue represent pioneering as well as new investigators, and also reflect the multidisciplinary nature of research in this exciting and rapidly progressing field.

It is well established that cellular lipid binding proteins serve central roles in cellular lipid uptake and metabolism. Evidence has been presented that various metabolic diseases, such as hyperlipidemia, atherosclerosis, insulin resistance, and diabetes, are characterized by malfunctioning or deficiencies in cellular lipid binding proteins. For better understanding of the action of lipids as signaling compounds and the role of lipids in intermediary metabolism, it is essential to have detailed knowledge of the interactions between lipids and their cognant binding proteins. In view of this growing interest in lipid-protein interaction, the 4th International Conference on Lipid Binding Proteins was held in Maastricht, The Netherlands, in June 2001. The proceedings of the previous three meetings have been published in Molecular and Cellular Biochemistry. The present focused issue of Molecular and Cellular Biochemistry comprises selected papers based on the lectures and posters presented during the 4th conference, and provides insight into the significance of these proteins for the functioning of the cell.

The breadth of modern biology is characterized by a comprehension of phenomena at many levels of organization. Such levels of understanding range from the organismal to the molecular. It is when all these levels can be discussed together that a sense of true achievement begins to be felt. The topical area of fatty acid transport and metabolism was the focus of the Third International Conference on Lipid-Binding Proteins held at the University of Minnesota in May 1997. This volume contains a sampling of the proceedings of this meeting.

In light of the increasing importance of these proteins and their ligands for our understanding of cellular growth, differentiation, and development, as well as of diseases such as obesity, insulin resistance, atherosclerosis, cancer, and inflammation, a team of internationally renowned editors and authors have compiled here the very first comprehensive book on these topics. They describe fatty acid-activated transcription factors as well as membrane and soluble fatty acid transporters, covering such aspects as structure and function, lipid-protein interaction, delivery of ligands, and the roles of these proteins in gene expression pertaining to the homeostatic and diseased states of cells and organs. Incorporating recent findings, this is indispensable for basic scientists, health professionals in industry and clinics as well as postgraduate students. Contributors among others: N.A. Abumrad, J.E. Schaffer, G. Schmitz, N.J. Brunskill, J. Storch, U. Seedorf, S. Mandrup, C.N.A. Palmer, T. Perlmann, H.I. Nebb, J. Bar-Tana, H. Kondo, C. Wolfrum, C. Kerkhoff , S. Farmer, E.J. Murphy, J.F.C. Glatz, P. Besnard, J.M. Stewart, A. Meirhaeghe, J. Plutzky, W. Wahli, R.A. Roberts