Regulation of E2 promoter binding factor 1 (E2F1) transcriptional activity through a deubiquitinating enzyme, UCH37.

E2F1 is tightly controlled by multiple mechanisms, but whether ubiquitination regulates its transcriptional activity remains unknown. Here we identify UCH37 as the first, to our knowledge, deubiquitinating enzyme for E2F1. UCH37 does not deubiquitinate UbK48 chains or affect E2F1 protein stability.

RNF144A, an E3 ubiquitin ligase for DNA-PKcs, promotes apoptosis during DNA damage.

Several ring between ring fingers (RBR) -domain proteins, such as Parkin and Parc, have been shown to be E3 ligases involved in important biological processes. Here, we identify a poorly characterized RBR protein, Ring Finger protein 144A (RNF144A), as the first, to our knowledge, mammalian E3 ubiquitin ligase for DNA-PKcs. We show that DNA damage induces RNF144A expression in a p53-dependent manner.

Regulation of E2F1 by APC/C Cdh1 via K11 linkage-specific ubiquitin chain formation.

E2F1 is a eukaryotic transcription factor that is known to regulate various cellular pathways such as cell cycle progression, DNA replication, DNA damage responses and induction of apoptosis. Given its versatile roles, a precise and tight regulation of E2F1 is very critical to maintain genomic stability. E2F1 is regulated both at transcriptional and posttranslational levels during cell cycle and upon DNA damage.

Crystal structure of the catalytic domain of UCHL5, a proteasome-associated human deubiquitinating enzyme, reveals an unproductive form of the enzyme.

Ubiquitin carboxy-terminal hydrolase L5 (UCHL5) is a proteasome-associated deubiquitinating enzyme, which, along with RPN11 and USP14, is known to carry out deubiquitination on proteasome. As a member of the ubiquitin carboxy-terminal hydrolase (UCH) family, UCHL5 is unusual because, unlike UCHL1 and UCHL3, it can process polyubiquitin chain. However, it does so only when it is bound to the proteasome; in its free form, it is capable of releasing only relatively small leaving groups from the C-terminus of ubiquitin.

Regulation and distribution of squirrel monkey chorionic gonadotropin and secretogranin II in the pituitary.

Secretogranin II (SgII) is a member of the granin family of proteins found in neuroendocrine and endocrine cells. The expression and storage of SgII in the pituitary gland of Old World primates and rodents have been linked with those of luteinizing hormone (LH). However, New World primates including squirrel monkeys do not express LH in the pituitary gland, but rather CG is expressed.