First Author | Watanabe Y | Year | 2009 |
Journal | FEBS J | Volume | 276 |
Issue | 21 | Pages | 6312-23 |
PubMed ID | 19788420 | Mgi Jnum | J:157802 |
Mgi Id | MGI:4436985 | Doi | 10.1111/j.1742-4658.2009.07339.x |
Citation | Watanabe Y, et al. (2009) A novel splicing variant form suppresses the activity of full-length signal transducer and activator of transcription 5A. FEBS J 276(21):6312-23 |
abstractText | Signal transducers and activators of transcription (STATs) regulate a variety of cellular functions, including differentiation and proliferation. STAT3 and STAT5 are known to play important roles in brain processes, such as energy homeostasis and neuronal development. We isolated a novel splicing variant of STAT5A from a cDNA library of the mouse brainstem. This variant, STAT5A_DeltaE18, lacked exon 18 and caused a frameshift in the C-terminus, resulting in deletion of a tyrosine phosphorylation site and a transactivation domain. Although the frameshift region had no characteristic motifs, it was highly serine/threonine-rich and contained a short proline-rich sequence. Expression of STAT5A_DeltaE18 was detected in the mouse brainstem, lung and thymus, but not in the mouse cerebrum or cerebellum. We developed a specific antibody against STAT5A_DeltaE18 and investigated the intracellular localization of this variant. STAT5A_DeltaE18 showed dot-like structures in the cytoplasm and could not translocate into the nucleus after prolactin treatment. STAT5A_DeltaE18 showed a strong tendency to aggregate, which led to coaggregation with STAT5A_full-length. This coaggregation inhibited the nuclear transport of STAT5A and suppressed prolactin-induced activation of STAT5A. |