Concurrently with and prior to the emergence of hematopoietic stem cells within the intraembryonic aorta, various types of hematopoietic progenitors are believed to arise in the extraembryonic yolk sac through a process of endothelial-to-hematopoietic transition.

Extracellular leucine-rich repeat and fibronectin type-III domain-containing protein 1 (ELFN1) is a synaptic adhesion protein, which regulates the precise positioning and physiological functions of metabotropic glutamate receptors (mGlus). Deficiency of the mGlu-ELFN1 interaction leads to severe pathological outcomes such as epilepsy and night blindness. However, the underlying mechanisms are largely unknown.

Obesity is increasingly recognized as a major factor contributing to female reproductive dysfunction and declining fertility. Excessive lipid accumulation and oxidative stress under obese conditions can disrupt mitochondrial homeostasis in oocytes, leading to impaired meiotic maturation, abnormal cytoskeletal organization, DNA damage, and reduced embryonic developmental competence. However, effective interventions targeting obesity-associated oocyte deterioration remain limited.

A recent study published in Protein & Cell by researchers from the Southern University of Science and Technology (SUSTech) provides critical structural and functional insights into the UBR4-KCMF1-Calmodulin (UKC) complex, revealing its pivotal role in protein quality control, cancer cell survival, and stress adaptation. The work, led by Professors Renhong Yan and Baotong Zhang, elucidates how this complex assembles and functions as an E4 ubiquitin ligase, extending ubiquitin chains on pre-tagged substrates to regulate protein degradation.

This work was funded by Key Research and Development Program, Ministry of Science and Technology of China (2022YFA1103103), National Natural Science Foundation of China (32488101, 32330030, 32370870, and 32170801), Fundamental Research Funds for the Central Universities (22120250336), and Fundamental and Interdisciplinary Disciplines Breakthrough Plan of the Ministry of Education of China (JYB2025XDXM508). The authors thank the Peak Disciplines (Type IV) of Institutions of Higher Learning in Shanghai, and the Frontier Science Research Center for Stem Cells, Ministry of Education for their support.; 4) Method of Research: experimental study; 5) Subject of Research: cell.

Neurons face an exceptional proteostasis challenge because their extreme polarization requires rapid proteome remodeling at distal axons and synapses. Rather than acting as separate systems, ribonucleoprotein granules and membranous organelles cooperate to form mobile translation platforms.