Other Proteins

SOCS-2 (Suppressor of cytokine signaling 2; also CIS-2 and SSI-2) is a 25 kDa member of the SOCS family of proteins. It is an SH2-domain containing cytoplasmic adaptor protein expressed by multiple cell types. It blocks receptor signaling by binding to phosphorylated tyrosines in the cytoplasmic domain of select receptors, including the receptors for leptin, IGF-I and GH. Human SOCS-2 is 198 amino acids (aa) in length and contains one SH2 domain (aa 48?156) and a SOCS box (aa 160?198) that mediates interaction with elongin B or C of the E3 ubiquitin ligase complex. There is one splice variant that shows an Arg-rich eight aa substitution for aa 31?39. Full-length SOCS-2 is 94% and 96% aa identical to mouse and porcine SOCS-2, respectively.

Seems to inhibit myoblast differentiation. Transcriptional repressor of E-box-dependent transactivation of downstream myogenic bHLHs genes.

Sec13 is a ubiquitously expressed protein which participates in the formation of vesicles in the COPII complex with Sec23p.Sec24p, Sar1p and Sec31. The COPII vesicle budding complex was first described in the yeast system and was shown to provide coat proteins in the early secretory pathway. Sec13 is recruited to endoplasmic reticulum (ER) membranes where it forms a three dimensional cuboctahedron cage lattice structure by association with Sec31. This vesicular structure is necessary for ER-Golgi transport.

RUNX3, also called CBFA3, AML-2 or PEBP2-alpha C, is a member of the Runt domain family of nuclear transcriptional regulators. All of the RUNX proteins form dimers with CBF-beta. The runt domain (aa 54-186) is required for DNA binding, while a pro/ser/thr-rich region (aa 191-415) transcriptionally activates target genes. Isoform 2 has an alternate 19 aa in place of the N-terminal 5 aa of isoform 1. The 415 aa Human RUNX3 shares 91% aa identity with mouse or rat RUNX3. RUNX3 is necessary for growth control of gastric epithelium, neurogenesis of dorsal root ganglia, and T cell differentiation. RUNX3 expression is frequently mutated in tumors and appears to be silenced by methylation.

Plays an important role in homologous strand exchange, a key step in DNA repair through homologous recombination. Binds to single and double-stranded DNA and exhibits DNA-dependent ATPase activity. Catalyzes the recognition of homology and strand exchange between homologous DNA partners to form a joint molecule between a processed DNA break and the repair template. Binds to single-stranded DNA in an ATP-dependent manner to form nucleoprotein filaments which are essential for the homology search and strand exchange (PubMed:26681308). Part of a PALB2-scaffolded HR complex containing BRCA2 and RAD51C and which is thought to play a role in DNA repair by HR. Plays a role in regulating mitochondrial DNA copy number under conditions of oxidative stress in the presence of RAD51C and XRCC3.

Protein transport. Probably involved in vesicular traffic.

The small GTPases Rab are key regulators of intracellular membrane trafficking, from the formation of transport vesicles to their fusion with membranes. Rabs cycle between an inactive GDP-bound form and an active GTP-bound form that is able to recruit to membranes different sets of downstream effectors directly responsible for vesicle formation, movement, tethering and fusion. RAB5A is required for the fusion of plasma membranes and early endosomes (PubMed:10818110, PubMed:14617813, PubMed:16410077, PubMed:15378032). Contributes to the regulation of filopodia extension (PubMed:14978216). Required for the exosomal release of SDCBP, CD63, PDCD6IP and syndecan (PubMed:22660413). Regulates maturation of apoptotic cell-containing phagosomes, probably downstream of DYN2 and PIK3C3.

May be involved in melanosomal transport and docking. Involved in the proper sorting of TYRP1. Involved in peripheral melanosomal distribution of TYRP1 in melanocytes; the function, which probably is implicating vesicle-trafficking, includes cooperation with ANKRD27 and VAMP7 (By similarity). Plays a role in the maturation of phagosomes that engulf pathogens, such as S.aureus and M.tuberculosis (PubMed:21255211). Plays an important role in the control of melanin production and melanosome biogenesis (PubMed:23084991). In concert with RAB32, regulates the proper trafficking of melanogenic enzymes TYR, TYRP1 and DCT/TYRP2 to melanosomes in melanocytes (By similarity).

Regulates endocytic recycling. May exert its functions by interacting with multiple effector proteins in different complexes. Acts as a major regulator of membrane delivery during cytokinesis. Together with MYO5B and RAB8A participates in epithelial cell polarization. Together with RAB3IP, RAB8A, the exocyst complex, PARD3, PRKCI, ANXA2, CDC42 and DNMBP promotes transcytosis of PODXL to the apical membrane initiation sites (AMIS), apical surface formation and lumenogenesis (By similarity). Together with MYO5B participates in CFTR trafficking to the plasma membrane and TF (Transferrin) recycling in nonpolarized cells. Required in a complex with MYO5B and RAB11FIP2 for the transport of NPC1L1 to the plasma membrane. Participates in the sorting and basolateral transport of CDH1 from the Golgi apparatus to the plasma membrane. Regulates the recycling of FCGRT (receptor of Fc region of monomeric Ig G) to basolateral membranes.