Subunit Heterogeneity of Cytoplasmic Dynein: Differential Expression of 14 kDa Dynein Light Chains in Rat Hippocampus

• Published in: The Journal of neuroscience Vol. 21; no. 15; pp. 5501 - 5512
• Main Authors: Chuang, Jen-Zen, Milner, Teresa A, Sung, Ching-Hwa
• Format: Journal Article
• Language: English
• Published: United States Soc Neuroscience 01.08.2001; Society for Neuroscience
• Subjects: Animals; Antibody Specificity; Brain Chemistry; Cell Line; Cerebral Cortex - cytology; Cerebral Cortex - metabolism; Cytoplasm - metabolism; Dendrites - metabolism; Dendrites - ultrastructure; Dentate Gyrus - metabolism; Dentate Gyrus - ultrastructure; Dyneins - biosynthesis; Dyneins - chemistry; Dyneins - genetics; Eye Proteins; Hippocampus - cytology; Hippocampus - metabolism; Humans; Immunohistochemistry; Macromolecular Substances; Microtubule Proteins - biosynthesis; Microtubule Proteins - chemistry; Microtubule Proteins - genetics; Microtubule-Associated Proteins; Microtubules - metabolism; Microtubules - ultrastructure; Nuclear Proteins; Organelles - metabolism; Organelles - ultrastructure; Precipitin Tests; Presynaptic Terminals - metabolism; Presynaptic Terminals - ultrastructure; Protein Biosynthesis; Protein Subunits; Proteins - chemistry; Proteins - genetics; Pyramidal Cells - cytology; Pyramidal Cells - metabolism; Rats; Rats, Sprague-Dawley; t-Complex Genome Region
• ISSN: 0270-6474; 1529-2401
• DOI: 10.1523/jneurosci.21-15-05501.2001

Cytoplasmic dynein is a multi-subunit protein complex in which each subunit is encoded by a few genes. How these subunit isoforms are assembled and regulated to mediate the diverse functions of cytoplasmic dynein is unknown. We previously have shown that two highly conserved 14 kDa dynein light chains, Tctex-1 and RP3, have different cargo-binding abilities. In this report, coimmunoprecipitation revealed that Tctex-1 and RP3 were present in mutually exclusive dynein complexes of brain. Two specific antibodies were used to examine the localization of these two dynein light chains in adult rat hippocampal formation and cerebral cortex. By light microscopy, Tctex-1 and RP3 immunoreactivities exhibited distinct and almost complementary distribution patterns in both brain regions. In hippocampal formation, Tctex-1 immunoreactivity was most enriched in somata of newly generated granule cells and scant in the mature granule and pyramidal cell somata. In contrast, RP3 immunoreactivity was abundant in pyramidal and granule cell somata. Ultrastructural analysis of the dentate gyrus revealed both dynein light chains were associated with various membranous organelles that often were affiliated with microtubules. In addition, Tctex-1 and RP3 immunoreactivities were preferentially and highly enriched on membranous organelles and/or vesicles of axon terminals and dendritic spines, respectively. These results suggest that dynein complexes with different subunit composition, and possibly function, are expressed differentially in a spatially and temporally regulated manner. Furthermore, Tctex-1 and RP3 may play important roles in synaptic functions.