Growth factor receptor-bound protein 2; Adapter protein that provides a critical link between cell surface growth factor receptors and the Ras signaling pathway; Belongs to the GRB2/sem-5/DRK family.

Mitogen-activated protein kinase kinase kinase kinase 4; Serine/threonine kinase that may play a role in the response to environmental stress and cytokines such as TNF-alpha. Appears to act upstream of the JUN N-terminal pathway. Phosphorylates SMAD1 on Thr-322 (By similarity); Belongs to the protein kinase superfamily. STE Ser/Thr protein kinase family. STE20 subfamily.

Thioredoxin-dependent peroxide reductase, mitochondrial; Thiol-specific peroxidase that catalyzes the reduction of hydrogen peroxide and organic hydroperoxides to water and alcohols, respectively. Plays a role in cell protection against oxidative stress by detoxifying peroxides.

Protein disulfide-isomerase A6; May function as a chaperone that inhibits aggregation of misfolded proteins. Negatively regulates the unfolded protein response (UPR) through binding to UPR sensors such as ERN1, which in turn inactivates ERN1 signaling (By similarity). May also regulate the UPR via the EIF2AK3 UPR sensor (By similarity). Plays a role in platelet aggregation and activation by agonists such as convulxin, collagen and thrombin (By similarity). Belongs to the protein disulfide isomerase family.

Ubiquitin-like modifier-activating enzyme 1; Catalyzes the first step in ubiquitin conjugation to mark cellular proteins for degradation through the ubiquitin-proteasome system. Activates ubiquitin by first adenylating its C-terminal glycine residue with ATP, and thereafter linking this residue to the side chain of a cysteine residue in E1, yielding a ubiquitin-E1 thioester and free AMP. Essential for the formation of radiation-induced foci, timely DNA repair and for response to replication stress. Promotes the recruitment of TP53BP1 and BRCA1 at DNA damage sites.

SUMO-activating enzyme subunit 2; The heterodimer acts as an E1 ligase for SUMO1, SUMO2, SUMO3, and probably SUMO4. It mediates ATP-dependent activation of SUMO proteins followed by formation of a thioester bond between a SUMO protein and a conserved active site cysteine residue on UBA2/SAE2 (By similarity); Belongs to the ubiquitin-activating E1 family.

Crk-like protein; May mediate the transduction of intracellular signals.

Mitogen-activated protein kinase kinase kinase kinase 1; Serine/threonine-protein kinase, which may play a role in the response to environmental stress (By similarity). Appears to act upstream of the JUN N-terminal pathway. May play a role in hematopoietic lineage decisions and growth regulation. Able to autophosphorylate. Together with CLNK, it enhances CD3-triggered activation of T-cells and subsequent IL2 production. Belongs to the protein kinase superfamily. STE Ser/Thr protein kinase family. STE20 subfamily.