Both Ser361 phosphorylation and the C‐arrestin domain of thioredoxin interacting protein are important for cell cycle blockade at the G1/S checkpoint

Abstract

Thioredoxin interacting protein (TXNIP) is a novel tumor suppressor that is down‐regulated in several cancer tissues and tumor cell lines. Overexpression of TXNIP causes cell cycle arrest at the G1/S checkpoint in the hepatocellular carcinoma cell line HuH‐7. TXNIP contains putative phosphorylation sites, but the effects of its phosphorylation have not been fully characterized. TXNIP also contains two α‐arrestin domains (N‐arrestin and C‐arrestin) whose functions are not fully understood. Here, we reveal an association between TXNIP and cell cycle regulatory proteins (p27 kip1 , Jun activation domain‐binding protein 1 (JAB1), Cdk2, and cyclin E), suggesting its participation in cell cycle regulation. We observed phosphorylation of TXNIP and used both in vivo and in vitro kinase assays to demonstrate that TXNIP can be phosphorylated by p38 mitogen‐activated protein kinase. Furthermore, we also identified Ser361 in TXNIP as one of the major phosphorylation sites. Cell cycle analysis showed that Ser361 phosphorylation participates in TXNIP‐mediated cell cycle arrest. In addition, the C‐arrestin domain may also play an important role in cell cycle arrest. We also showed that phosphorylation at Ser361 may be important for the association of TXNIP with JAB1 and that the C‐arrestin domain is necessary for the nuclear localization of this molecule. Collectively, these studies reveal that TXNIP participates in cell cycle regulation through association with regulatory proteins, especially JAB1, and that C‐arrestin‐dependent nuclear localization is important for this function. This work may facilitate the development of a new cancer therapy strategy that targets TXNIP as a key molecule inhibiting cancer cell growth via cell cycle blockade at the G1/S checkpoint.

Long-Term IGF1 Stimulation Leads to Cellular Senescence via Functional Interaction with the Thioredoxin-Interacting Protein, TXNIP

“…In the context of cell cycle regulation, we provide evidence that, under stress conditions, TXNIP mediates cell cycle arrest, mainly in the G1 phase. These results corroborate previous reports [ 38 , 39 , 67 ]. On the other hand, IGF1 signaling pathways are evolutionarily conserved to promote cell cycle progression in multiple species [ 68 ].…”

The Cellular Composition of Bovine Coccygeal Intervertebral Discs: A Comprehensive Single-Cell RNAseq Analysis

“…C1QTNF3 has been described as downstream factor of HIF-1alpha which plays an essential role in cartilage development [ 78 ]. TXNIP as part of the TXNIP-NLRP3 inflammasome has been related to IVD degeneration [ 79 ], yet it is known for its pleiotropic effects as it plays an important role in the energy metabolism [ 80 ] and in cell cycle regulation [ 81 ]. Semaphorin 4A ( SEMA4A ) was also expressed in cell Cluster 5.…”

The α‐arrestin family of ubiquitin ligase adaptors links metabolism with selective endocytosis

“…Some ARRDCs interact with the ESCRT-I protein Tumour susceptibility gene 101 (TSG101) [Nabhan et al, 2012;Anand et al, 2018], or with the ESCRT-III-associated apoptosis-linked gene-2 interacting protein X (ALIX) [Dores et al, 2015], which confers to them specific properties that will be discussed below (see part on arrestin-mediated vesicles). ARRDC3, ARRDC4 and TXNIP interact with ; may be involved in a TXNIP-mediated cell cycle arrest Kamitori et al (2018) clathrin [Shea et al, 2012;Wu et al, 2013]. TXNIP can additionally interact with the AP-2 adaptor complex [Wu et al, 2013].…”