MYOSIN LIGHT-CHAIN KINASE - EXPRESSION IN NEURONS AND UP-REGULATION DURING AXON REGENERATION

Myosin light-chain kinase (MLCK) regulates actin-myosin II interaction s in nonskeletal muscle cells, and the use of specific pharmacological inhibitors has implicated MLCK in retinal growth cone motility and ne urite out-growth. To further establish the existence and functions of MLCK in neurons, we isolated cDNAs encoding two forms of goldfish MLCK that were differentially expressed in the brain and gut and rye seque nced the form most abundantly expressed in the brain (GFMLCK1). In sit u hybridization with a cRNA probe specific to GFMLCK1 revealed widespr ead expression in CNS neurons, including tectal periventricular neuron s and cerebellar and medullary neurons. After optic nerve crush, expre ssion was markedly increased in the retinal ganglion cells. Expression peaked during the phase of axonal out-growth, which, when taken toget her with our previous pharmacological studies, further supports a role for MLCK in growth cone motility. (C) 1996 John Wiley & Sons, Inc.