Regulation of growth hormone biosynthesis by Cdk5 regulatory subunit associated protein 1-like 1 (CDKAL1) in pituitary adenomas.

Regulation of growth hormone biosynthesis by Cdk5 regulatory subunit associated protein 1-like 1 (CDKAL1) in pituitary adenomas. Endocr J. 2019 Jun 11;: Authors: Takesue Y, Wei FY, Fukuda H, Tanoue Y, Yamamoto T, Chujo T, Shinojima N, Yano S, Morioka M, Mukasa A, Kuratsu J, Tomizawa K Abstract CDK5 regulatory subunit associated protein 1-like 1 (CDKAL1) is a tRNA-modifying enzyme that catalyzes 2-methylthiolation (ms2) and has been implicated in the development of type 2 diabetes (T2D). CDKAL1-mediated ms2 is important for efficient protein translation and regulates insulin biosynthesis in pancreatic cells. Interestingly, an association between T2D and release of growth hormone (GH) has been reported in humans. However, it is unknown whether CDKAL1 is important for hormone production in the pituitary gland. The present study investigated the role of CDKAL1 in GH-producing pituitary adenomas (GHPAs). CDKAL1 activity was suppressed in GHPAs, as evidenced by a decrease in ms2, compared with non-functioning pituitary adenomas (NFPAs), which do not produce specific hormones. Downregulation of Cdkal1 using small interfering and short hairpin RNAs increased the biosynthesis and secretion of GH in rat GH3 cells. Depletion of Cdkal1 increased the cytosolic calcium level via downregulation of DnaJ heat shock protein family (Hsp40) member C10 (Dnajc10), which is an endoplasmic reticulum protein related to calcium homeostasis. This stimulated tr...
Source: Endocrine Journal - Category: Endocrinology Tags: Endocr J Source Type: research