CREM-Dependent Transcription in Male Germ Cells Controlled by a Kinesin
Abstract
ACT is a LIM-only protein expressed exclusively in round spermatids, where it cooperates with transcriptional activator CREM in regulating various postmeiotic genes. Targeted inactivation of CREM leads to a complete block of mouse spermiogenesis. We sought to identify the regulatory steps controlling the functional interplay between CREM and ACT. We found that ACT selectively associates with KIF17b, a kinesin highly expressed in male germ cells. The ACT-KIF17b interaction is restricted to specific stages of spermatogenesis and directly determines the intracellular localization of ACT. Sensitivity to leptomycin B indicates that KIF17b can be actively exported from the nucleus through the Crm1 receptor. Thus, a kinesin directly controls the activity of a transcriptional coactivator by a tight regulation of its intracellular localization.
- Publication:
-
Science
- Pub Date:
- December 2002
- DOI:
- 10.1126/science.1077265
- Bibcode:
- 2002Sci...298.2388M
- Keywords:
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- MOLEC BIOL