Polyclonal Antibodies: HEPL, ATM

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Rabbit polyclonal antibody to HEPL, a novel Cas family protein

HEPL8

The Cas (Crk-associated substrate) scaffolding protein family contains three defined members: p130Cas/BCAR1, HEF1/Cas-L/NEDD9, and Efs/Sin. Elevated expression of p130Cas/BCAR1 has been linked to poor prognosis in breast cancer, while overexpression of HEF1/NEDD9/Cas-L recently been found to potently induce metastatic melanoma. Mechanistically, the best-studied functions of the Cas family proteins include regulation of attachment-dependent survival signaling or anoikis, and regulation of cell motility and invasion, although there is evidence for additional roles for some of these proteins in control of cell cycle, growth factor signaling, cell differentiation, and bacterial and viral infection.

Researchers at Fox Chase Cancer Center have identified a new gene of Cas family proteins that they named as HEPL (HEF1-Efs-p130Cas-like). They show that the HEPL mRNA and protein are expressed in cultured cell lines and tumors, and that HEPL has biological activities similar to those of other family members in influencing cell attachment and movement. The identification of HEPL provides an important context to further studies of this increasingly important protein group. They have developed Rabbit-polyclonal antibody against this newly identified protein which can detect endogenous HEPL from a number of cancer cell lines.

ApplicationsWB (overexpressed protein) and IP (overexpressed and endogenous protein). Not effective for IF or WB on lysates containing endogenous protein.
  
Specificity:Western blot with a variety of human cell lines confirms that the antibody is specific for human Mad2; other species specificity has not yet been determined
  
Immunogen:Rabbit polyclonal antibody to HEPL was generated using a peptide corresponding to HEPL amino acids 773-786.
  
Citation:Singh MK, Dadke D, et al. "A novel Cas family member, HEPL, regulates FAK and cell spreading," Mol Biol Cell (in press) published online ahead of print February 6, 2008.

Anti-Ataxia Telangiectasia Mutated (ATM) Antibodies

Ataxia telangiectasia mutated or ATM is a member of an emerging group of genes that encode proteins involved in the

ATM

 checkpoint control pathway. Maintenance of genomic stability is an essential process requiring proteins that detect diverse types of DNA damage and enzymes that repair the defects accurately. Repair of DNA damage is intimately linked to cell cycle control and apoptosis. Checkpoint proteins can halt cell cycle progression allowing sufficient time to allow a cell to make repairs. If the damage is beyond repair, the arrested cells are programmed to self-destruct so that undesirable mutations are not propagated.

The checkpoint proteins characterized to date (e.g. p53, GADD45, and p21 ) appear to be quite far down the checkpoint control pathway from the initial signal induced by DNA damage. ATM, on the other hand, appears to play an early role in activating checkpoint control and in regulating apoptosis. Thus, ATM might play a pivotal role in determining whether cells should remain arrested to allow for repairs or should die if the damage is beyond repair. How the ATM protein might function to activate checkpoint control or induce apoptosis remains to be elucidated. It is likely that the protein acts as a dispatcher that receives and transmits signals linking genome integrity and cell growth control. Such a possibility is supported by the observed similarity between the C-terminal region of the ATM protein and the kinase domain of phosphotidylinositol 3 kinase, a protein known to participate in signal transduction.

Clones:

Three rabbitt polyclonal abs (Ab1, Ab2, and Ab3) have been made against nonoverlapping domains of ATM expressed as bacterial fusion proteins. Ab1 was raised against the RAD3 domain (aa 2138-2739), Ab2 was raised against the kinase domain (aa 2740-3056), and Ab3 was raised against a domain of unknown function near the N terminus (aa 247-521)

  
Applications:

WB and IF

  
Citation:Gately DP, Hittle JC, et al. "Characterization of ATM expression, localization, and associated DNA-dependent protein kinase activity," Mol Biol Cell, 9(9):2361-74 1998 Sep; 9(9):2361-74. [PMID: 9725899]