We investigated which isoform of protein kinase C (PKC) is responsible to metabolic inhibition i the guinea pig taenia caeci with respect to their phosphorylation levels. By Western blot analysis using isoform-specific antibodies, at least four isoforms of PKC, ct, 62, E and C were identified in the taenia. Prolonged metabolic inhibitlon of hypoxia, hypoxia+glucose depletion, and addition of cy...

Classical nonhomologous end joining (C-NHEJ) is a major mammalian DNA double-strand break (DSB) repair pathway that is required for assembly of antigen receptor variable region gene segments by V(D)J recombination. Recombination activating gene endonuclease initiates V(D)J recombination by generating DSBs between two V(D)J coding gene segments and flanking recombination signal sequences (RS), w...

DNA double-strand break (DSB) repair by non-homologous end joining (NHEJ) in human cells is initiated by Ku heterodimer binding to a DSB, followed by recruitment of core NHEJ factors including DNA-dependent protein kinase catalytic subunit (DNA-PKcs), XRCC4-like factor (XLF), and XRCC4 (X4)-DNA ligase IV (L4). Ku also interacts with accessory factors such as aprataxin and polynucleotide kinase/...

Human Werner Syndrome is characterized by early onset of aging, elevated chromosomal instability, and a high incidence of cancer. Werner protein (WRN) is a member of the recQ gene family, but unlike other members of the recQ family, it contains a unique 3'-->5' exonuclease activity. We have reported previously that human Ku heterodimer interacts physically with WRN and functionally stimulates W...

In this paper we present a method of attacking public-key cryptosystems (PKCs) on tamper resistant devices. The attack makes use of transient faults and seems applicable to many types of PKCs. In particular, we show how to attack the RSA, the ElGamal signature scheme, the Schnorr signature scheme, and the DSA. We also present some possible methods to counter the attack.

The Common Data Security Architecture (CDSA) is a general security service architecture which has been standardized by the Open Group. This paper compares the CDSA CAPI to another well known low-level CAPI, RSA’s PKCS #11 (Cryptoki). Both CDSA and Cryptoki are low-level interfaces which satisfy criteria established by the NSA’s CAPI Team. However, CDSA provides a security services infrastructur...

This paper introduces a new adaptive chosen ciphertext attack against certain protocols based on RSA. We show that an RSA private-key operation can be performed if the attacker has access to an oracle that, for any chosen ciphertext, returns only one bit telling whether the ciphertext corresponds to some unknown block of data encrypted using PKCS #1. An example of a protocol susceptible to our ...

Smartcards and PKCS #11 are an appealing solution for combined storage and certificate management at the enduser level. Many applications use PKCS #11 primitives for security reasons: a popular browser, like Netscape Navigator contain a PKCS #11 cryptographic module that plays a critical role in secure web surfing and e-mail signing and encryption. Nevertheless, most market-ready solutions ([SM...

Non-homologous end-joining (NHEJ) and homologous recombination (HR) are the two prominent pathways responsible for the repair of DNA double-strand breaks (DSBs). NHEJ is not restricted to a cell-cycle stage, whereas HR is active primarily in the S/G2 phases suggesting there are cell cycle-specific mechanisms that play a role in the choice between NHEJ and HR. Here we show NHEJ is attenuated in ...