Connexin43 phosphorylation in brain, cardiac, endothelial and epithelial tissues

AbstractGap junctions, composed of proteins from the connexin family, allow for intercellular communication between cells in essentially all tissues. There are 21 connexin genes in the human genome and different tissues express different connexin genes. Most connexins are known to be phosphoproteins. Phosphorylation can regulate connexin assembly into gap junctions, gap junction turnover and channel gating. Given the importance of gap junctions in development, proliferation and carcinogenesis, regulation of gap junction phosphorylation in response to wounding, hypoxia and other tissue insults is proving to be critical for cellular response and return to homeostasis. Connexin43 (Cx43) is the most widely and highly expressed gap junction protein, both in cell culture models and in humans, thus more research has been done on it and more reagents to it are available. In particular, antibodies that can report Cx43 phosphorylation status have been created allowing temporal examination of specific phosphorylation events in vivo. This review is focused on the use of these antibodies in tissue in situ, predominantly looking at Cx43 phosphorylation in brain, heart, endothelium and epithelium with reference to other connexins where data is available. These data allow us to begin to correlate specific phosphorylation events with changes in cell and tissue function. This article is part of a Special Issue entitled: The Communicating junctions, composition, structure and characteristics

Protein kinase C spatially and temporally regulates gap junctional communication during human wound repair via phosphorylation of connexin43 on serine368

Phosphorylation of connexin43 (Cx43) on serine368 (S368) has been shown to decrease gap junctional communication via a reduction in unitary channel conductance. Examination of phosphoserine368 (pS368) in normal human skin tissue using a phosphorylation site–specific antibody showed relatively even distribution throughout the epidermal layers. However, 24 h after wounding, but not at 6 or 72 h, pS368 levels were dramatically increased in basal keratinocytes and essentially lost from suprabasal layers adjacent to the wound (i.e., within 200 μm of it). Scratch wounding of primary human keratinocytes caused a protein kinase C (PKC)-dependent increase in pS368 in cells adjacent to the scratch, with a time course similar to that found in the wounds. Keratinocytes at the edge of the scratch also transferred dye much less efficiently at 24 h, in a manner dependent on PKC. However, keratinocyte migration to fill the scratch required early (within <6 h) gap junctional communication. Our evidence indicates that PKC-dependent phosphorylation of Cx43 at S368 creates dynamic communication compartments that can temporally and spatially regulate wound healing

Bostonia: The Boston University Alumni Magazine. Volume 15

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Alcohol-related Discussions during General Medicine Appointments of Male VA Patients Who Screen Positive for At-risk Drinking

OBJECTIVE: This study describes primary care discussions with patients who screened positive for at-risk drinking. In addition, discussions about alcohol use from 2 clinic firms, one with a provider-prompting intervention, are compared. DESIGN: Cross-sectional analyses of audiotaped appointments collected over 6 months. PARTICIPANTS AND SETTING: Male patients in a VA general medicine clinic were eligible if they screened positive for at-risk drinking and had a general medicine appointment with a consenting provider during the study period. Participating patients (N = 47) and providers (N = 17) were enrolled in 1 of 2 firms in the clinic (Intervention or Control) and were blinded to the study focus. INTERVENTION: Intervention providers received patient-specific results of positive alcohol-screening tests at each visit. MEASURES AND MAIN RESULTS: Of 68 visits taped, 39 (57.4%) included any mention of alcohol. Patient and provider utterances during discussions about alcohol use were coded using Motivational Interviewing Skills Codes. Providers contributed 58% of utterances during alcohol-related discussions with most coded as questions (24%), information giving (23%), or facilitation (34%). Advice, reflective listening, and supportive or affirming statements occurred infrequently (5%, 3%, and 5%, of provider utterances respectively). Providers offered alcohol-related advice during 21% of visits. Sixteen percent of patient utterances reflected “resistance” to change and 12% reflected readiness to change. On average, Intervention providers were more likely to discuss alcohol use than Control providers (82.4% vs 39.6% of visits; P = .026). CONCLUSIONS: During discussions about alcohol, general medicine providers asked questions and offered information, but usually did not give explicit alcohol-related advice. Discussions about alcohol occurred more often when providers were prompted