Characterization of Cytoplasmic Dynein Light-intermediate Chain isoforms in Rat Testis.

Abstract

Keywords: LIC/spermatogenesis/isoform/motor protein/in situ hybridization ABSTRACT.We obtained three kinds of novel cytoplasmic dynein light-intermediate chain (LIC) isoforms from rat testis and brain by reverse transcription polymerase chain reaction (RT-PCR). The primers for RT-PCR were designed according to LIC-2 (LIC 53/55) (15). In one novel isoform, the 42 bp specific sequence named TDL was inserted between 1,106 and 1,107 nucleotides (nts) of LIC-2, whereas the 57 bp sequence corresponding to LIC-2 1,339-1,395 nts (BDL) was absent. The TDLand BDLregions were specifically digested with restriction enzymatic treatment and followed by subcloning of non-digested CDNA band in testis and brain, producing an isoform without TDL and BDLregions. BDLspecific RT-PCRof testis CDNAfollowed by sequencing produced an isoform with two specific regions. By Northern blot hybridization using TDLand BDL specific antisense oligo DNAprobe, 4.4, 3.5, and 2.0 kb of signals were detected. With both TDLand BDL probes, the 2.0 kb signal was intensely detected in testis, while the 4.4 kb was defected in brain. This indicates that TDLand BDLare derived from the same size of mRNAs.In situ hybridization method using these probes showed that all seminiferous epithelial cells, especially late pachytene spermatocytes, were positive, indicating that LIC 53/55 isoforms were coexpressed in these cells. These findings indicate that LIC 53/55 isoforms provide a variety of dynein subunits, and thus may regulate the dynein-dependent intracellular transport system.

Light Intermediate Chain 1 Defines a Functional Subfraction of Cytoplasmic Dynein Which Binds to Pericentrin

“…1A, open boxes labeled A and B); the human LIC2 isoforms have all appeared in GenBank (23). We have obtained no comparable pattern in our LIC1 cDNAs.…”

Phosphorylation by cdc2-CyclinB1 Kinase Releases Cytoplasmic Dynein from Membranes

“…Four to five dynein light-intermediate chains (DLICs) are present per CD complex, binding to an N-terminal portion of the DHC near to the DIC binding site (15). DLICs show great diversity owing to the presence of two genes (DLIC1 and DLIC2), multiple spliced variants, and differential phosphorylation (15)(16)(17)(18)(19)(20)(21).…”

Intracellular Localization of the Microtubule-Associated Motor Proteins Kinesin and Cytoplasmic Dynein in Rat Sertoli Cells.

“…It has become obvious that some types of the family relate to respective organelles [32][33][34], but the molecular family of cytoplasmic dynein has not been clearly identified intercellularly. However, cytoplasmic dynein is composed of multiple subunits, such as heavy chains, intermediate chains, light intermediate chains, and light chains [35], and these subunits have some isoforms [26,27,36,37]. While the functions of these isoforms remain unclear, these molecular variations, including KIFs, may relate to the regulation of various organelle transport systems.…”