Expression of retrograde transport proteins during oligodendrocyte

Abstract

Using a combination of subcellular fractionation and suppression subtractive hybridization, we found that a high molecular weight dynein light intermediate chain‐2 mRNA copurifies with myelin basic protein mRNA in rat brain myelin. We used a combination of subtraction efficiency and Northern blot analysis to show that other dynein (dynein heavy chain, dynein intermediate chains 1 and 2 and dynein light intermediate chain‐1) and dynactin (arp‐1, p150glued, dynamitin, CLIP‐170 and capB1) mRNAs do not copurify with these mRNAs in rat brain myelin. We used immunofluorescence and Western blotting to show that all of these proteins are expressed by cultured oligodendrocytes. These results suggest that of all the dynein/dynactin proteins synthesized in oligodendrocytes, only one, dynein light intermediate chain‐2, is synthesized in the cell's processes (near sties of myelin sheath assembly). Consequently, the addition of dynein light intermediate chain‐2 molecules to other dynein/dynactin proteins at sites of myelin sheath assembly may influence retrograde transport initiated at these distal sites.Acknowledgements: Supported by grant RG2944A5/1 from the National Multiple Sclerosis Society.