Role of small leucine zipper protein in hepatic gluconeogenesis and metabolic disorder

CREB3 protein family: the promising therapeutic targets for cardiovascular and metabolic diseases

Significant advancements in cardiovascular and metabolic disease research have been made with the CREB3 protein family. Studies have revealed that members of this family are crucial in the development of these diseases, contributing to the regulation of lipid metabolism, inflammation, and vascular function. These studies provide useful information for future therapeutic strategies in cardiovascular and metabolic diseases.

Theoretical prediction of nanomolar and sequence-selective binding of synthetic supramolecular cucurbit[7]uril to N-terminal Leu-containing tripeptides

Molecular recognition towards peptides and proteins with high affinity by synthetic supramolecular hosts is important but challenging. In this work, we investigate the molecular recognition of the synthetic cucurbit[7]uril (CB[7]) to 17 designed N-terminal Leu-containing tripeptides in aqueous medium by molecular dynamics (MD) simulation and screen out tripeptides with high binding affinity. It is found that, compared to LGG, only the third residue is Arg (R), the binding affinity of CB[7] to LGR reaches nanomolar level with binding equilibrium constant (K_a) of 1.1 × 10⁹ M^-1. The CB[7] recognition to the N-terminal Leu-containing tripeptides is highly sequence dependent; whether changing the sequence order (from LGR to LRG) or increasing the sequence length (from LGR to LGGR), K_a decreases by about three orders of magnitude. Interestingly, substituting N-terminal Leu for its isomer Ile, the binding of CB[7] to tripeptides weakens significantly with K_a decreasing by 3-8 orders of magnitude. Thus CB[7] can effectively distinguish N-terminal Leu-containing tripeptides from N-terminal Ile-containing tripeptides. Importantly, we predict that when R is as C-terminus, regardless of N-terminal residue being of aromatic type or Leu, the binding strength is always close to the nanomolar level. Therefore, R can be introduced to rationally design novel peptides with high binding affinity to CB[7] in practical applications.

Small leucine zipper protein functions as a modulator for metabolic reprogramming of colorectal cancer cells by inducing nutrient stress-mediated autophagy

In multiple cancers, autophagy promotes tumor development by recycling intracellular components into metabolic pathways. Autophagy-induced metabolic reprogramming and plasticity lead to cancer cell survival and resistance to anticancer therapy. We investigated the role of small leucine zipper protein (sLZIP) in autophagy and cell survival under nutrient-deficient conditions in colorectal cancer (CRC). sLZIP was induced by nutrient stress and increased the transcription of microtubule-associated protein 1A/1B-light chain 3 (LC3), by directly binding to its promoter. Under nutrient stress conditions, sLZIP activated autophagy and promoted the survival of CRC cells. sLZIP induced metabolic reprogramming of CRC cells, to activate glutaminolysis and the tricarboxylic acid cycle. sLZIP also enhanced the autophagic degradation of Keap1 and the nuclear accumulation of Nrf2, leading to NQO1 expression, for maintenance of redox homeostasis. sLZIP-knockout CRC cells exhibited impaired autophagy induction in the glycolytic inhibition state. Xenograft mice lacking sLZIP showed decreased tumor growth, by rendering CRC cells sensitive to glycolysis inhibition. The expression of sLZIP and LC3B was highly elevated in tumors of CRC patients compared to that in normal tissues, and correlated with the progression of CRC. These findings suggest that sLZIP drives autophagy and metabolic reprogramming to promote colorectal tumorigenesis.