Ubiquitin signalling Archives - Laboratory Notes

K63‑Linked Ubiquitination

admin — Sat, 22 Aug 2026 15:03:04 +0000

K63‑linked ubiquitination is a non‑degradative signalling modification that assembles scaffold‑like ubiquitin chains regulating DNA repair, NF‑κB activation, receptor endocytosis and autophagy. Built by UBE2N/UBE2V1 and specialised E3 ligases, K63 chains coordinate dynamic cellular responses without targeting proteins for proteasomal degradation.

The post K63‑Linked Ubiquitination appeared first on Laboratory Notes.

Mdm2 (Mouse Double Minute 2 Homologue)

admin — Fri, 21 Aug 2026 11:51:23 +0000

Mdm2 is a RING‑type E3 ubiquitin ligase that controls p53 stability through ubiquitination, nuclear export and proteasomal degradation. By interacting with p53, Mdmx/Mdm4 and ARF, Mdm2 regulates DNA‑damage responses, cell‑cycle progression and oncogenesis, making it a central determinant of tumour development and genome stability.

The post Mdm2 (Mouse Double Minute 2 Homologue) appeared first on Laboratory Notes.

U‑Box Ubiquitin Ligase

admin — Fri, 21 Aug 2026 09:34:52 +0000

U‑box ubiquitin ligases are RING‑type E3 enzymes with a modified U‑box domain that enables zinc‑independent ubiquitin transfer. Key members such as CHIP, PRPF19 and UBOX5 regulate chaperone‑mediated protein quality control, DNA‑damage repair and cellular stress responses, making the U‑box family essential for proteostasis and genome stability.

The post U‑Box Ubiquitin Ligase appeared first on Laboratory Notes.

HECT Ubiquitin Ligase

admin — Fri, 21 Aug 2026 08:57:06 +0000

HECT ubiquitin ligases are catalytic E3 enzymes that form a thioester intermediate with ubiquitin, allowing precise control of ubiquitin‑chain architecture. Through NEDD4‑family ligases, HERC proteins and HUWE1, the HECT class regulates receptor endocytosis, DNA‑damage signalling, proteostasis and diverse cellular stress responses.

The post HECT Ubiquitin Ligase appeared first on Laboratory Notes.

K48‑Linked Ubiquitination

admin — Thu, 20 Aug 2026 22:13:18 +0000

K48‑linked ubiquitination is the principal degradation signal in eukaryotic cells, directing proteins to the 26S proteasome. Built by E1, E2 and E3 enzymes, K48‑linked chains regulate protein turnover, cell‑cycle progression and DNA‑damage responses, forming a central mechanism for maintaining proteostasis and preventing toxic protein accumulation.

The post K48‑Linked Ubiquitination appeared first on Laboratory Notes.